fileHandleValidation: only one argument

This function is used once, where it takes one argument.
It actually only uses one argument
isCellOrChar: only one argument

inputParser uses a one-argument validation function,
and the second argument was not used
validation functions: help string shortened
m2t.cmdOpts -> ipp at the beginning

This cleans up the code quite a bit and makes typos less likely
Cleaned up input parser

A lot of entries had a single line of comment that stated the same
as the parameter name OR even had wrong information.
Since 99% of this information is already contained in the HELP text,
this reduces the redundant information.
Merge pull request #288 from egeerardyn/cleanup-input-parsing

Cleanup input parsing