SlsDetector: performance improvements:

* Add full PixelDepthCPUAffinityMap to/from string conversion
* Add multiple processing threads per recv. port (currently 4)
* Calculate intermediate buffers' affinity based on RecvCPUAffinity::Writers
* Use SSE2 SIMD for 4-to-8 bit expansion in Recv::Port callback
* Add Expand4InThreads, allow setting NbPortThreads to (default is 2)
* Add interchip gap in SIMD 4-to-8 bit expansion algorithm:
* Move FrameMap code to independent compilation unit
* Move Port Threads to the Receiver level
* Move geometry calculation code to Eiger::Geometry
* Remove intermediate buffer for 4-to-8 bit expansion
* Block Receiver::Port threads while Model::Recv::Thread work
* Support arbitrary number of threads, distribute with ThreadBalance

python @ 4928a7b2

-Subproject commit 9a88145bf0ef63ea079dc0db9904d9ef6dd25918
+Subproject commit 4928a7b23eae1bdb9e47d0e9c3c4e60403ecb06d

slsdetector @ e924a335

-Subproject commit b97d3bf28b2f346ff7ad740801f7b25f0cb10671
+Subproject commit e924a3357c23e7d2a1515e35fb270fceadad7e75