1. Disable automatic `git commit` GPG-signing, since that requires interaction.
This issue was encountered in practice by me, causing spurious test failures
2. In case path operands could turn out to start with dashes, escape the
operand list with '--'.
Do a straight test of detecting a real merge conflict as generated by git.
Test artificial conflict detection while pending merge without a real conflict.
Test artificial non-conflict non-detection in a resolved merge conflict.
Rename test_does_not_care... function to reflect what we want to care about.
Rename is_in_merge_conflict to is_in_merge since that is what it checks.
Several markup formats, such as Markdown or Re(Structured)Text
can format titles as text with '=' characters as double underlining,
like this:
```
My Page Title
=============
Lorem ipsum...
```
Rather that considering any line starting with seven '=' as a conflict marker,
require a space (or line-ending newline) after the equals.
This could still create a false positive for a seven character title,
like "Problem", but the markup formats generally allow extra '=' characters,
so by formatting the text like this:
```
Problem
========
Not...
```
these pre-commit warnings can be avoided.
Also updates the tests to add newlines for more realistic conflict files
(while a file might not end with a newline, conflict markers will).
Prevent false negative on test_does_not_care_when_not_in_a_conflict()
by making sure that README.md contains a line identical to a conflict string
(exactly seven '=' followed by a newline).
