minor build changes to support OSX

git-svn-id: https://roadrunnerlib.googlecode.com/svn/branches/refactor_modelgen@867 c0027639-9190-0b57-01eb-f09a03790dae
fix isnan inconsistency on Linux/Unix

git-svn-id: https://roadrunnerlib.googlecode.com/svn/branches/refactor_modelgen@868 c0027639-9190-0b57-01eb-f09a03790dae
updates to comply with unix standard linking convetions and add support for OSX
Merge uranus.chem.indiana.edu:~/src/roadrunner into refactor_modelgen_svn
enhance cross-platformness for OSX