[pvr] basic series recording support

@Jalle19, @xhaggi
I've extended the pvr api for some basic serie recording support.

This is not very well tested as no pvr client supports this yet of cource :-)
(Basic testing with faked timers and logging events sended to the pvr client)

Please don't merge this yet, I still may add some commits.
This is just an easy way for me to discuss the current implemantation with you guys.

When does the merge window for new features closes? 
I've exams in the next few weeks, so my time to work on this is very limited.

So about the implementation:
1) The most common serie types are supported and the pvr client can set them through a bitflag.

2) No new dialog/window added, so every skin should stay working!

3) Timersettings dialog is reworked so we can use that one now for creating serie recordings.
It's a lot more flexible now, only the appropriate settings are showed to the user and the others are hided.

4) When an epg based serie timer is opened with the 'timersetting' dialog, a few settings will be greyed out (read only) These are: strart time, end time, title, day, channel, they are set by the epg tag so it's not smart to let the user edit them (I guess). If a unknown type of timer is opened, everything will be read only. 

5) It would be nice if this dialog gets auto sized depending on the amount of items, but I've no idea how.

6) Adding a recording through the epg guide will still add a normal 'once' recording like it was before.
Personally I don't want to be asked for a serie recording every time :-)

7) So, adding an serie recording has to be done through the contex menu from the 'tv guide' or 'timer search' window. The user will find an "add advanced timer" button for this, also an "add simple timer" button will be present.

screenshots:
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A31%3A16.png
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A25%3A17.png
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A26%3A05.png
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A26%3A19.png
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A26%3A29.png
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A27%3A32.png
https://dl.dropboxusercontent.com/u/18133665/xbmc/screenshots/Schermafdruk%20van%202014-08-12%2021%3A27%3A49.png

AFAIK we called this "margin before/after" in the PVR settings, but use whatever makes most sense to natives. @jjd-uk