Updates for issue #68- creating new function to make recording functions uniform in how they work

[iwhiteley]

Created new parseInputVariable.m function that gives the user the option to call functions with no inputs, partial inputs, or complete. When given no, or partial, inputs, function asks the user to manually enter the values, if no value is entered, it will go to a default value provided. PSF.m, lens_paper.m, and uniform_slide.m have been updated to use this new function.

[raacampbell]

Can you remove stuff that is not part of the update. e.g. and .asv files and remove all commented out code such as that in parsePowerAndWavelength.m. Also please remove uniform_slide_test, which just tests input arguments and seems to only be needed for development.

[raacampbell]

Change list we discussed:

• sprintf line should include the default variable
• remove redundant function I wrote to handle the wavelength and power
• Move your new function to private
• remove redundant if statements
• update doc text in end-user files to reflect new call structure
• update doc text in the parser function to have an H1 line, no gap in comments, and a description of the input arguments,

[raacampbell]

I merged and then did some tidying, including reducing the repeated code in the parser function. b11a934a961b6e4e9cb0e136aac7fd0230957686