Add cosmostack program to stack many grf realizations of an input power spectrum.
Update program description, minor syntax changes.
fix typo in output message.
add option to specify line of sight axis
Add options for histogram binning.
fix error in distance function. rename a few variables. add more verbose output messages. move variable declarations closer to usage (inside loops).
add new grf generator that computes the grf naively, uses more memory and is slower but works as advertised. add option to cosmostack to choose grf generator
Add new cosmostack program to stack many grf realizations of an input power spectrum.

Add new class TestFftGaussianRandomFieldGenerator to naively, but correctly, produce grf realizations of an input power spectrum.
Update automake files, following changes to likely
Add -llikely explicitly for each bin target
Rebuild autoconf scripts
Make likely a configure dependency of the cosmo library
Add pkg_config file
Fix a typo that installed a .cc file to /usr/local/include/ instead of the .h file
* Update minimum required boost version from 1.45 to 1.49
* Rework autoconf to use newer boost.m4
* Rework autoconf to separate library and program dependencies
* Create pkg_config file