'Add to homescreen' feature on ipad with icon

add meta to support  ipad.  When add to home screen ,Stackedit can run
in standalone mode ,and can be an offline app even without connections.
update logo
Added Solarized light and dark theme.

- Themes share the common solarized.less base.
n branch master
Cleanup
Cleanup
Cleanup
CouchDB sync part 1
CouchDB sync provider part 2
Increased couchdb update time permissiveness
Merge branch 'couch' of bitbucket.org:benweet/stackedit into couch
Fixed couchdb tag support
Fixed html and css
Merge branch 'couch' of bitbucket.org:benweet/stackedit into couch
Merge branch 'master' of github.com:benweet/stackedit
Merge branch 'master' of https://github.com/kmb32123/stackedit
Fixes #533
Add comment handler in html sanitizer. Fixes #519
fixed outdated Dockerfile
avoid glob negations with gulp will reduce running time for `gulp jshint` from 13s to 3.5s

Also this brings down total time of build (running `gulp`) from 33s to 23s
Update of stacktrace dependency, gives payload optimization:

the recent version excludes /test directory which contained a giant jar file. This reduces size of bower-libs/stacktrace folder
from 7MB to ~150KB

See https://github.com/stacktracejs/stacktrace.js/pull/84