Added WebExt hook handler

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Added WebExt content handler on loadSubTemplate()

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Added WebExt include and start call.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Added Bootstrap theme css file into default theme

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Merge branch 'release-2.1' into WebExt