Merge pull request #111 from hwhw/SDL2

SDL2 support
create fonts dir in OUTPUT_DIR to avoid polluting mupdf
Merge pull request #112 from houqp/houqp-master

create fonts dir in OUTPUT_DIR to avoid polluting mupdf
add getPageRegions api in libk2pdfopt
Merge pull request #113 from chrox/master

add getPageRegions api in libk2pdfopt
add setBatteryState api for crereader
Merge pull request #114 from chrox/master

add setBatteryState api for crereader
follow typesetting taboo for CJK punctuations
Since there is no space character for word break in CJK typesetting,
line wrap can occur virtually between any two characters. But by
convention some punctuations are not allowed to be placed at the
begining of a line, and other punctuations are not allowed to be
placed at the end of a line. This patch implements two of these
rules.
Merge pull request #115 from chrox/master

follow typesetting taboo for CJK punctuations
clean up punctuation patch and fix floating CJK punctuation
Merge pull request #116 from chrox/master

clean up punctuation patch and fix floating CJK punctuation
Update sdcv (&apos; support)
Merge pull request #117 from thotypous/master

Update sdcv (&apos; support)
fix punctuation width calculation
Merge pull request #118 from chrox/master

fix punctuation width calculation
fix an infinite loop when upskip a left punctuation
Merge pull request #119 from chrox/master

fix an infinite loop when upskip a left punctuation
fix for PAM files when writing RGB, conversion RGB16->24/32

PAM writing for all RGB formats was broken (wrong max value of 256, it is in fact 255).

Also, conversion from RGB16 to RGB24 or RGB32 was also wrong due to a typo.
Merge pull request #120 from hwhw/fix-screenshot

fix for PAM files when writing RGB, conversion RGB16->24/32
add go back/forward method for credocument