Make it proper C
regtest: Update references also for tests that no longer crash

We are currently updating the refs only when we have checksums to
compare, but if a test used to crash there's no md5 file in refs.
write correct size in trailer dict

Bug #86063
Use Default colorspaces if present instead of Device colorspaces

Fixes part of #68986
Solve blend mode problem in CYMK and DeviceN for separable blend modes

Fixes part of #68986
Use correct LAB byte array for lcms input

Bug #86388
cofigure: print "no" instead of "auto" if lcms not found
The isfinite macro is defined on SunOS under c99

Bug #86869
warning: "_FILE_OFFSET_BITS" redefined

Bug #86870
Run dos2unix as suggested by Volker Grabsch
0.29.0
Cairo backend added to Qt4 wrapper
Setting default Qt4 backend to Cairo
Forcing subpixel rendering in Cairo backend
Enabling slight hinting in Cairo Backend

Originally suggested at:
http://bugs.freedesktop.org/show_bug.cgi?id=3307#c20