Updates required to make final version of DR7 products

[jotaylor]

• Update README with more accurate install & product instructions. NOTE: I am not finished with README updates, just wanted to commit what I already have.
• Improve target name matching when it is needed for HLSP filenames and headers.
• Change stisblazefix wrapper to accept an output file rather than a directory. This allows the user to specify and extension and write an x1d rather x1f if desired. The x1fs were causing some confusion for the HLSP creation code.
• Consistent usage of the text WARNING in all caps. This helps me with checking the output from HLSP creation code when grepping.
• Change EPOCH keyword to G_EPOCH
• Adjust starting wavelength for abutting STIS/E140M to avoid very noisy region.
• Remove obsolete calls to get_coords in ullyses coadd
• Update package requirements, these were required for a fresh install.

[jotaylor]

I tested two example targets, AV-456 and CVSO-58. Products for both targets were identical using new HASP version vs. DR7 HLSPs created last week.