left/right spacing logic for reflowable columnized content, including support for optimum (maximum) text line width, and fallback to single page on minimum width threshold
Merge remote-tracking branch 'origin/develop' into feature/textWidthMargins

Conflicts:
	js/views/reflowable_view.js
removed useless comments, void html+body spacing specifically to give away margin control to columnised renderer (prior this change, normalisation of content spacing to void blank pages was limited to bottom trailing whitespace, now uniform)
Merge remote-tracking branch 'origin/develop' into feature/textWidthMargins
better column width min/max thresholds (same as iBooks)
Merge remote-tracking branch 'origin/develop' into feature/textWidthMargins
Firefox, Chrome, Safari tested with this height value, okay now (blank columnpage issue).
Merge remote-tracking branch 'origin/develop' into feature/textWidthMargins

Conflicts:
	js/views/reflowable_view.js
"forced" synthetic spread or single page, vs. non-opinionated choice (fallback) see #65
aargh, typo!! (sorry for the noise)
font size adjust for native iOS apps on high-res iPad
minor tweak to cater for ultra-small SDK Launcher OSX font size
tweaks (sorry for multiple commits, pulling code accross devices during tests)
Merge remote-tracking branch 'origin/develop' into feature/textWidthMargins

Conflicts:
	js/views/reflowable_view.js
Merge remote-tracking branch 'origin/develop' into feature/textWidthMargins
support for rendition:viewport as fallback #86 #84
Merge branch 'develop' of https://github.com/readium/readium-shared-js into develop
addresses #89, although we should verify support for images-in-spine on all target browsers, due to possible discrepancies in how browsers wrap images in HTML template + Readium code that attempts to manipulate the "image" spine item as if it were a regular content document
minor comments adjustments (images in spine use-case)
partially addresses #90 (only Firefox)