Ignore distribution tarballs
Add no-op xerbla implementation and shared library
Add lisp foreign-function binding macros

* Based on BLAS/LAPACK matrix/vector representations and conventions
Lisp input/output foreign parameters
Refactor foreign binding
Lisp bindings for pass-by-reference
Wrap level 1 BLAS
Matrix transpose in wrappers
Use CFFI type translators to perform call by reference
Add m4 directory
Defer linking against blas and lapack to library user
Explicitly load blas and lapack libraries
Refactor some kinematics
Fix makefile dependencies and enable silent rules
Quaternion slerp test
Add differential quaternion functions
Test quaternion/velocity conversions
Implement mem_region-allocated linked lists
Remove f77 code
Add vararg functions to multiply rot. and tf. matrices