[trunk] Update file extension function to handle cases where filename containes multiples dots.

Update issue 250
[trunk] Import patch from sumatrapdf team. This adds alpha handling. This patch changes ABI.

Update issue 225
[trunk] Import patch from sumatrapdf team. This patch adds new colorspace handling.

Update issue 225
[trunk] Import patch from sumatrapdf team. Add a new function to check color box.

Update issue 225
[trunk] Import patch from sumatrapdf team. Add detection for testcase 1802.pdf.SIGSEGV.36e.894

Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 4035.pdf.SIGSEGV.d8b.3375
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 2539.pdf.SIGFPE.706.1712
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 1610.pdf.SIGSEGV.59c.681
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 2.pdf.SIGFPE.706.1112
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 451.pdf.SIGSEGV.ce9.3723
Update issue 225
[trunk] Import patch from sumatrapdf team. Original commit is 5b0c9985e3359aca9b3fcfd94424166aa61a141a.
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 3635.pdf.asan.77.2930
Update issue 225
[trunk] Import (ugly) patch from sumatrapdf team. This feels like a hack rather than a solution.
Fixes issue 226
[trunk] Import patch from sumatrapdf team. This handle testcase 2977.pdf.asan.67.2198
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle some testcase with no input dataset, but changes looks ok.
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle some Part-2 compliant file, by being more tolerant in COLR box. No testcase for now.
Fixes issue 247
[trunk] Import patch from sumatrapdf team. Start using new color space when found.
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 1851.pdf.SIGSEGV.ce9.948
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 1888.pdf.asan.35.988
Update issue 225
[trunk] Import patch from sumatrapdf team. This handle testcase 1336.pdf.asan.47.376
Update issue 225