Merge remote-tracking branch 'ruslan/makefile'
Merge remote-tracking branch 'ruslan/spupng'
Removed Problem compiling c file in Visual Studio

Also moved -I include flags in INCLUDE variable since preprocessor
needs the location of header file, while compiling c to object file.

In src/dvb_subtitle_decoder.h added cpp guard

changed dvb cpp extension to c and removed some extra space at end of
line.
Merge remote-tracking branch 'upstream/master'
fix teletext detection by parsing all desc tag

Fix #20