Optimize pictures with optipng.
Optimize svgs with scour.
Add shellscript for optimization.
Improve IE Compatibility

Added meta tags from HTML5 Boiler Plate to improve compatibility with IE7+. This fixes the issues with rendering.
The "lost password" field depends on OC_USER_BACKEND_SET_PASSWORD

so it should only be visible for users with a supporting backend.
Abstract the session away in a class
Use the new session wrapper
Fix session not working error
check fix if session start is successfull
provide a dummy session for CLI
fix syntax error
Merge pull request #3488 from zafi/master

The "lost password" field in the personal setting depends on OC_USER_BACKEND_SET_PASSWORD
Merge pull request #2778 from Kondou-ger/optimize_pictures

Optimize pictures with optipng.
Merge pull request #3179 from pawl/patch-1

Improve IE Compatibility
merge master into sessionclass
implement ArrayInterface with Session
fixed encryption session namespace to avoid problems
Merge branch 'sessionclass' of https://github.com/owncloud/core into sessionclass
fixed missing convert to new session handler
didn't mean to commit this yet