Improves performance of CO2 function

Also adds groundwork for performance testing
Merge pull request #31 from lukecampbell/perf-work

Improves performance of CO2 function
Starts updating cdt functions

Updates ctd_sbe16plus_tempwat to utilize numexpr
Merge pull request #32 from blazetopher/start_ctd_updates

Starts updating cdt functions
Finishes CO2 funciton improvements
Merge pull request #33 from lukecampbell/perf-work

Finishes CO2 funciton improvements
Patches pygsw ver
Improvements to qc_functions

Starts improving qc_functions
* Adds rolling_window to utils module - efficient generation of windows along an array
* Adds 'strict_validation' flags to all dataqc_* functions
* Improved internal looping of dataqc_spiketest
Merge pull request #34 from blazetopher/qc_func_improvements

Improvements to qc_functions
Refactors some tests and begins tests for qc profiling
Merge pull request #35 from lukecampbell/qc-performance

Refactors some tests and begins tests for qc profiling
Refactors more performance testing code
Merge pull request #36 from lukecampbell/qc-performance

Refactors more performance testing code
Refactored the perfomance structure
Merge pull request #37 from lukecampbell/qc-performance

Refactored the perfomance structure
More performance tests
Merge pull request #38 from lukecampbell/qc-performance

More performance tests
we want 2 days not 20
Cython extension testing
Cython extension