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");
}
}
}
[---------------------------------------------------------------------]

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<?xml version="1.0" encoding="UTF-8" standalone="no"?>

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<PyFile>

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  <variables/>

     4

  <globals>

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<![CDATA[

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from threading import Thread

     7

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def OnConnectButton(self, event):

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  def OnWiiConnected(mac_addr):

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    self.label_2.SetLabel(

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      "Wiimote %s connected"%mac_addr 

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      if mac_addr else 

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      "Wiimote connection failed !")

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  def WiiConnected(mac_addr):

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    wx.CallAfter(OnWiiConnected,mac_addr)

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  Thread(target = Connect_Wiimote, args = (WiiConnected,)).start()

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  self.label_2.SetLabel("Press wiimote 1+2")

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  event.Skip()

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def OnDisconnectButton(self, event):

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  Disconnect_Wiimote()

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  self.label_2.SetLabel("Wiimote disconnected")

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  event.Skip()

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]]>

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  </globals>

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  <init>

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<![CDATA[

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]]>

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  </init>

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  <cleanup>

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<![CDATA[

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]]>

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  </cleanup>

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  <start>

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<![CDATA[

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]]>

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  </start>

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  <stop>

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<![CDATA[

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]]>

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  </stop>

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</PyFile>