Disable Python extension in First steps example

use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

This code could be possible reused on low-end targets with limited RAM.

code to generate lookup table:
[---------------------------------------------------------------------]

/* CRC lookup table and initial state. */
uint32_t crc32_table[256];

/* Generate CRC32 lookup table. */
void GenerateCRC32Table(void)
{
unsigned int i, j;
/* Use CRC-32-IEEE 802.3 polynomial 0x04C11DB7 (bit reflected). */
uint32_t poly = 0xEDB88320;

for (i = 0; i <= 0xFF; i++)
{
uint32_t c = i;
for (j = 0 ; j < 8 ; j++)
c = (c & 1) ? (c >> 1 ) ^ poly : (c >> 1);
crc32_table[i] = c;
}
}

void main(void)
{
GenerateCRC32Table();
int j=0;
for(int i=0; i<256; i++) {
printf("0x%08X, ", crc32_table[i]);
if (++j >= 8) {
j = 0;
printf("\n");
}
}
}
[---------------------------------------------------------------------]

Merged in masterschlumpf/beremiz/wx3-fix (pull request #37)

Fix an exception with wx-3.0-gtk3 in PLCOpenEditor when generating ST files

Approved-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>

Fix an exception on wx-3.0-gtk3 in PLCOpenEditor when generating ST files.

On Python2.7 with WX3.0 and GTK3, an assertionError rises on generating a ST file if the name is already set. The first generation works without problems, if you generate the file a second one, PLCOpenEditor tries to open the file
save dialog with the pre entered name from last run. Then the following assertion pops up:

PyAssertionError: C++ assertion "volDummy.empty() && pathDummy.empty()" failed at ./src/common/filename.cpp(568) in Assign(): the file name shouldn't contain the path

This fix reduces the filepath of the ST file the to the filename. Now it works fine.

Fix typos in function names

update links to matiec and beremiz repos in README

fix zoom-in/zoom-out using mouse wheel

regression introduced by 2393:235f847be37e "python3 support: pylint, W1619 #(old-division) division w/o __future__ statement"

better pylint complain workaround

check_sources.sh makes me become even less productive

Added stub axis_s type in EtherLAB CiA402 support code, until Motion Contol Library comes back

Allow using one XSD based target description for many targets. Target description XSD can now use %(target_name)s to refer to target name.

Fix previous commit : Using wx.CallAfter shouldn't have been necessary, and was a symptom of failing evaluator's deadlock detection.

Fix startup of wxGlade base HMI. Wx calls were issued from non-wx thread (main).

Reworked chunk based transfer to support duplicated files (i.e. files with same content, but different names)

Fixed deadlock in runtime's Worker. Was discovered while using WAMP and PYRO simultaneously.

Add a debugger token to SetTraceVariables and GetTraceVariables to prevent crash an inconsistant data in case of multiple connections. Last connection now takes over existing connections's debug, and first connected IDE gets a wrning.

Fixed deadlock when using Wx together with Twisted in runtime.

Split IDE's frame OnCloseFrame() into TryCloseFrame() and OnCloseFrame(), to help further customization

fixed exception happening randomly just after showing discovery panel.

fixed exception happening when connecting to empty URI, and set URI through URI Editor Dialog popping up becaue empty.

Merged Mario's modbus fix : Modbus plugin: reset periodic activation timer when overrun occurs (delays due to communication errors, ...)

Modbus plugin: reset periodic activation timer when overrun occurs (delays due to communication errors, ...)

Disable MDNS:// scheme support. Also prevent discovery pannel to produce some. For now it seems that that feature is unused, and could be a security issue.

Added support to PYROS in Zeroconf discovery and publish. For now, PYRO://mdnsname._tcp.local. URI are broken, and discovery panel generate IP based URI by default.

PyroServer: fixed naming of class, and reorganized methods in order to ease subclassing, in case of customization of service publication on the local network (i.e. zeroconf)

Fix exception dialog with non recognized URI schemes

Fixed runtime's reconnecting loop not stopping when re-configuring WAMP.
In case WAMP was already trying to connect without success and user change WAMP configuration through web interface, previous ReconnectingClient wasn't stopped.

Removed nonsense code, that I should have check more in details before merging m(

Allow easier monkey patching of WAMP connector Session class

Expose new PLCObject API members to WAMP interface.