Merge pull request #1 from tarvidsson/development

- Compile cli on macosx, corrected printf format strings.
added wsa_get_freq_inv function
renamed get_freq_inv to get_spec_inv
added 'get spec inv' function to CLI
Merge pull request #2 from tarvidsson/development

Development
fixed bug in get_spec_inv
Merge branch 'spec_inver_scpi' into development
Merge remote-tracking branch 'upstream/development' into development