Followup for https://github.com/greenmanspirit/journal.txt/issues/20

Added test modes passed and failed. This will make it show only passed or failed results respectively. The totals still print regardless of mode. I also fixed some of the assert outputs that were wrong.
Followup for https://github.com/greenmanspirit/journal.txt/issues/20

I have refactored test_functions and commented everything. I also added the license to vim.
Followup for https://github.com/greenmanspirit/journal.txt/issues/20

I made it so only '', passed, failed and both are valid modes. No assuming like I was before where something unrecognized would just be both.
Apparently, you can't have the commit message window up and change a file already listed for the commit. This is a usage message.
Followup for https://github.com/greenmanspirit/journal.txt/issues/20

Changed echo to printf so that this vim can create files with no content so I can test saving an empty file. Echo put a newline in, printf does not. I also put in a flag of no_write in VALUE to simulate opening a new file and quitting without saving anything.
Followup for https://github.com/greenmanspirit/journal.txt/issues/20

I added the last few tests that I can think of and a supporting assert.