Implements a proper uninstall confirmation page

Implements a proper uninstall confirmation page, which replaces the
previous JS based warning.

The confirmation page is a preparation of the functionalty to delete
dependencies as well (selectively not by default).

Implements and uses the possibility to dry run the uninstall process.

Implements a vague and not fully reliable distinction between
uninstalled and installed modules in the data table.

Implements some minor fixes and optimisations.
Adds some code optimisations
Fixes small table head glitch when not in advanced mode
Changes uninstall confirm url structure

adds some code in preparation for installing/uninstalling/updating
dependencies
fixes minor things
Prepares code for module in module installation
Fixes issue #5

see: https://github.com/weworkweplay/ProcessJSONInstaller/issues/5
Fixes minor assumptions
Changes confirm warnings to messages
Fixes notice when template label is not set
Merge pull request #7 from owzim/master

Implements a proper uninstall confirmation page and adds some code optimisations