In gaxpy_ext_recursive: now using two-scale relationship instead of project to get child coefficients of left node.
removed unnecessary macro from testgaxpyext.cc
Changes to inner_ext methods:
    * Added user option to stop refinement at level of leaf nodes
    * Changed truncate_tol(thresh, key) to thresh
    * Now starting at initial_level instead of at leaf nodes of "host"
      function.
    * Documentation for inner_ext and gaxpy_ext methods
Merge pull request #100 from richford/master

Performance enhancements for inner_ext() methods