Add tool to fix HiRISE index FILE_RECORDS and ROWS entries

[garydoranjr]

@stevenlujpl discovered that the incorrect number of FILE_RECORDS and ROWS are reported in HiRISE cumulative index files. We can create a command line tool to automatically update these entries to reflect the correct values.

[stevenlujpl]

I think this issue should be completed. The changes haven't been merged into the master branch yet. @garydoranjr, could you please take a look at this PR (#43) and let me know if there is anything else I should change? If not, I think we should merge the PR into the master branch and close this issue. Thanks.