Don't hijack "fast" UI refresh w/ the REAGL stuff
Ask for a full refresh when clearing HL

Helps avoiding ghosting, especially on REAGL devices.

re #1119
fix memory calculation for cache insert decision, simplify drawing/rendering
Make ScrollTextWidget updates regional

Because I like breaking stuff in fun & interesting ways :D
pull latest base

contains fix/workaround for freeing memory used by MuPDF
Fix flipping mode refreshes

Don't do regional footer refreshes when we're in flipping mode.
There's probably a more elegant/correct way to handle this, but this
does the job ;).
Fix #1140
Fix partial refreshes on older Kobo devices

Fix #1146 (regression).
Merge pull request #1144 from hwhw/master

Memory related fixes
Merge pull request #1145 from NiLuJe/master

Some more refresh fixes...
fix #1142 by adding 'show page overlap' option for EPUB doc
And 'show page overlap' option is disabled in "page" mode for EPUBs,
and in fit to page/*height zoom mode for PDFs.
fix #1149 by adding 'Network setting' in filemanager
screensaver options only apply to Kobo devices
dismiss 'Opening file' dialog once reader view is ready
fix #1154
And koreader release version is normalized to a 10 digits containing
a four digits year field followed by a two digits month field followed
by a four digits revision field like "2014041079".
Merge pull request #1152 from chrox/fix_1142

fix #1142 by adding 'show page overlap' option for EPUB doc
Merge pull request #1153 from chrox/fix_1149

fix #1149 by adding 'Network setting' in filemanager
Merge pull request #1159 from chrox/fix_1155

dismiss 'Opening file' dialog once reader view is ready
Merge pull request #1160 from chrox/fix_1154

fix #1154