some fixes and a lot of updated stuff from koreader-base

new blitbuffer/framebuffer handling from koreader-base
plus a few other fixes and bits.

Not working right yet.
removed libjpeg
add libjpeg-turbo-1.3.0
first adaptions to the README for new infrastructure

not yet complete
restructuring, new (actually, old) features
strerror for posix_h.lua
bugfix
add BGR32 blitbuffer support
add information getting for running timers
remove old reference
rename to kVNCviewer
update README
remove reference to geometry.lua