1) Add flexible seeking support (including absolute) for memory block queues and...

1) Add flexible seeking support (including absolute) for memory block queues and playback streams
2) Add support to synchronize multiple playback streams
3) add two tests for 1) and 2)
4) s/PA_ERROR/PA_ERR/
5) s/PA_ERROR_OK/PA_OK/
6) update simple API to deal properly with new peek/drop recording API
7) add beginnings of proper validity checking on API calls in client libs (needs to be extended)
8) report playback buffer overflows/underflows to the client
9) move client side recording mcalign stuff into the memblockq
10) create typedefs for a bunch of API callback prototypes
11) simplify handling of HUP poll() events

Yes, i know, it's usually better to commit a lot of small patches instead of a
single big one. In this case however, this would have contradicted the other
rule: never commit broken or incomplete stuff.

*** This stuff needs a lot of additional testing! ***

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@511 fefdeb5f-60dc-0310-8127-8f9354f1896f