cleanup etherlab: pep8, W293 blank line contains whitespace

cleanup etherlab: pep8, E228 missing whitespace around modulo operator

cleanup etherlab: pep8, E401 multiple imports on one line

cleanup etherlab: pep8, E265 block comment should start with '# '

cleanup etherlab: pep8, W291 trailing whitespace

convert some etherlab source files to unix format

cleanup etherlab: pep8, E722 do not use bare except

Ignore cache files and generated test reports

Update Beremiz translations and list of translators

Added Turkish, Romania, Portuguese, Polish, Dutch, Hungarian.
Most existed translation are updated.

Use the list of supported by app translations instead of supported translations by wx

This will make possible to translate application into locales, that
are not explicitly supported by wx: for example, 'pl' or 'bn_BD', 'bn_IN'.

Suppress message box in case current locale is unsupported or missing in wx

Beremiz can still be translated into it using own locales
available in './locale'.

Add commands to pull translation from transifex

tx - transifex cli client should be installed in the system.
It's free software and is available in Debian archive.

Run following commands:
1. Init your authorization token
$ make transifex_init

2. Pull translations
$ make transifex_pull

Add custom dialog to add/edit comment block in graphical editors

That allows to edit comment and immediately see how it'll be shown on wiresheet.

Cleanup examples so they look clean, nice and almost the same on Windows and GNU/Linux

use the same font size on Windows and GNU/Linux

use nice and pretty mono font in graphical languages (SFC, FBD, LD) as well

it looks like that was original idea, but some bug squashed in and
default font was used for POU.

at the same time fix use of mono font in the header of Variable panel
for SFC/FBD/LD POUs.