blocks: Added multiply_matrix_ff

This block maps inputs to outputs by matrix multiplication.
Also includes QA.
blocks: Added multiply_matrix_cc
volk: add NEON protokernels
volk: dekludging asm setup, round 1
docs: Restructured intro page, added some manual pages
Merge remote-tracking branch 'mbant/docs/structure' into docs/structure
coverity 1207185: vocoder: unitialized summed squared error
cmake: fix to make FindPortaudio compatible with CMake 2.6.
cmake: fix component force on to work as expected
gr-digital: remove redundant source file
Merge branch 'maint'
cmake: make build type check insensitive to case
Merge remote-tracking branch 'martin/blocks/mult_matrix'
cmake: coalesce EXPAND macros into 3 common macros, and switch to using those; simplifies code and makes maintenance easier.
digital: Removed spurious XML
build: adding fstream include files for pedantic compilers.
qtgui: bringing in line with required Qt 4.4.

setGraphicsSystem was introduced in 4.5; doing a version check before its use.
Merge branch 'maint' of git.gnuradio.org:gnuradio into maint
Merge branch 'maint'
volk: removing unused variables in neon