Pre-release of Auryn 0.8.0

This release comes with numerous upgrades, performance improvements and bug fixes.

Performance history from Auryn 0.7.0 to Auryn 0.8.0:

Complete refactor of SyncBuffer for parallel performance
Complete refactor of AurynStateVector as a template class
Refactor of IFGroup and AIFGroup to new AurynVector interface
Changes memory alignment of AurynVector data for SIMD optimizations
Improved handling of ComplexMatrix states and
Performance optimizations in ComplexMatrix
Performance optimizations in SparseConnection
Performance optimizations in Connection
Performance optimizations in AurynVector
API changes in Connection
Adds groupstate variables to SpikingGroup
Adds AllToAllConnection
Adds IafPscExpGroup
Adds CubaIFGroup
Adds Izhikevich neuron model als IzhikevichGroup
Adds BinaryStateMonitor and the decoder tool "aubs" (a better name might be in order though)