major change in PMS handling

PlexAPI
- g_PMS to store server properties per aTV
- declare, search, access functions (class-like?)
- discover: checks GDM + MyPlex
- intermediate XMLFromMultiplePMS: add PMS address, similar to aTV
WebServer
- removed: try to discover
XML_converter
- discover whn aTV app starts - ie PlexConnect.xml is requested
- handle PMS() data in URL, IMAGEURL
- rewritten PMDCOUNT, PMSNAME
Settings
- removed "toggle PMS"

Known issue…
when cancelling out/at the end of video replay, the PrePlayScreen is
not found ->PMS unknown.
fix for commit #401: updatePag() contains correct URL to provide PMS address
fix for commit #401: PMS search.
a bunch of changes addressing the "accesstoken" issue
couple of fixes and improvements

Dahlgren's commits:
- 59d1163bc7 - Fixed key typo
- 0c3dfb381b - Make sure MyPlex PMS is updated within the last two days
- 4b5f21cd3 - Handle error where thre are no local or MyPlex PMS present
Thanks!

force discover/PlexGDM when signing into/out of Myplex
add MyPlex template to collect all remote/shared servers
send server-based accesstoken to .js instead of MyPlex authorisation.

- add new special char to {{VAL}}: % to access PMSProperty, might even
be used to replace {{PMSNAME}}, {{ADDR_PMS}}
- rework application.js to better show we are using server-based
accesstoken
add setting for bitrate limit of remote/shared MyPlex servers
decouple PMS discovery from requesting PlexConnect.xml
optimization: don't add '/PMS( )' to URL if PMS is unspezified
grab and store name/uuid for manual defined server, too
Movie List fix
Merge remote-tracking branch 'upstream/master'