More RAM in backend

Still more IOBOUND errors. Measures taken:

a. Removed 'noapic' from kernel options (at boot). This reverts back to FC3 canned bootup.

b. Increased internal write buffers. TFW_DEF_BUF_SIZE now (8*1024*1024) in RingBuffer.cpp, set SetWriteBufferSize(16*1024*1024) in tv_rec.cpp.

c. Added 512MB PC3200 CL2.5 ram stick. Now 768MB DDR in backend.