Merge pull request #102 from matthesrieke/dev

adjust thumbnail urls for AGOL maps
Merge branch 'dev' of https://github.com/enviroCar/enviroCar-www into dev
Merge pull request #108 from enviroCar/master

Update URL of server
Updated texts regarding app download.
Added missing word
Merge pull request #111 from enviroCar/dev

Merge branch 'dev'
Removed Youtube Video Iframe border, fixed z-index
Merge pull request #3 from enviroCar/master

re-align
Merge pull request #4 from enviroCar/dev

Dev
Update lang_de.php
Update lang_en.php
Merge pull request #113 from matthesrieke/dev

Adjust max Android version.
Changed font to Open Sans, adapted registration form, started modifying navbar and landing page
Merge remote-tracking branch 'origin/dev' into dev
Added border to Navbar, included font link in header-start
Moved Youtube Video into a modal
Added dynamic sign(ed) in menu to navbar
Changed the submenu of the about page
Fixed bugs with video modal and adapted the two header files
A .js file is now included in every page <pagename>.js if the file exists