Vagrrant: Add virtual development environment

Note that you have to run 'mkdir app/cache' before running 'vagrant up'
Merge branch 'support/1.11' into next
Vagrant: Use icinga-packages instead of RepoForge for installing Icinga
Vagrant: Fix default manifest including 'graphite'
Vagrant: Mount `app/data/tmp/' with appropriate permissions

The directory `app/data/tmp' must be writable for the webserver user
because icinga-web writes cache files into this directory.
Add support for Apache 2.4 in the example configs.

Fixes #6289
Don't register a "beforeunload" event on each ajax request

Fixes a memory leak mostly noticeable during automatic content refreshs
Merge branch 'support/1.11' into next
Merge branch 'support/1.11' into next

Conflicts:
	etc/apache2/icinga-web.conf.in
Merge branch 'support/1.11' into next

Conflicts:
	.gitignore
Merge branch 'support/1.11' into next
Fix spec file for SLES 11
Merge branch 'support/1.11' into next
Removed old minified javascript file from pub/

Fixes #7419
Merge branch 'support/1.11' into next
Session: Do not write session on every request

This speed up the gui by at least 20%.

Refs #7718
Session: Update empty data results in error

SQLSTATE[HY093]: Invalid parameter number: number of
bound variables does not match number of tokens.

Refs #7718
Session: Fix write to database if date not initialized

Refs #7718
Merge branch 'fix/session-write-7718' into next

Fixes #7718
WelcomeCronk: Fix default cronk setting

Default cronk is defined in userpreferences.xml:

<ae:parameter name="org.icinga.cronk.default">portalHello</ae:parameter>

If you use an other cronk which uses parameters the old method did not
respect params sections. The new way (which is implemented in
CronkListingPanel.js) loads all cranks from remote (also hidden cronks)
and create a valid record (xml and database cronk)

Refs #7719