[FIX] fix display issue in safari

safari needs to use css rules prefixed with -webkit-
[IMP] add warning when removing non global favorite
Revert "[IMP] change button style for installable modules"

This reverts commit 6f0d94e1c2c0188c45d4f51cdc95264093f0ce14.
[FIX] various layout fixes for web client

* fallback support for browser without calc,
* invisible pager in some cases