The diff --patch parser was missing some edge case where Git would
encode non-ASCII chars in path names as octals, but these weren't
decoded properly.

    \360\237\222\251.txt

Decoded via utf-8, that will return:

    💩.txt

Don't allow `, ` prefixes or suffixes in messages.

Fixes #438

Opt to split lines by the new line character instead of letting
`splitlines()` do this. This helps catch the issue when there are
special characters in the line, particular the commit summary section.

Need spaces in Emacs style encoding comment

Fixes #426

Although it's hard to see, PEP-0263 does have ws delimiting the 'coding' string.
This commit will fix the root cause of (at least) one bug: https://lists.fedoraproject.org/archives/list/eclipse-sig@lists.fedoraproject.org/thread/5XQ5JRHG6DPPMGRDU7TA2AO4EYS2H7AG/

Who would have thought we ever go 2.0 ;).

Add support for getting "aware" datetime info

Specifically "string_escape" does not exist as an encoding anymore.

This specifically covers the cases where unsafe chars occur in path
names, and git-diff -p will escape those.

From the git-diff-tree manpage:

> 3. TAB, LF, double quote and backslash characters in pathnames are
>    represented as \t, \n, \" and \\, respectively. If there is need
>    for such substitution then the whole pathname is put in double
>    quotes.

This patch checks whether or not this has happened and will unescape
those paths accordingly.

One thing to note here is that, depending on the position in the patch
format, those paths may be prefixed with an a/ or b/.  I've specifically
made sure to never interpret a path that actually starts with a/ or b/
incorrectly.

Example of that subtlety below.  Here, the actual file path is
"b/normal".  On the diff file that gets encoded as "b/b/normal".

     diff --git a/b/normal b/b/normal
     new file mode 100644
     index 0000000000000000000000000000000000000000..eaf5f7510320b6a327fb308379de2f94d8859a54
     --- /dev/null
     +++ b/b/normal
     @@ -0,0 +1 @@
     +dummy content

Here, we prefer the "---" and "+++" lines' values.  Note that these
paths start with a/ or b/.  The only exception is the value "/dev/null",
which is handled as a special case.

Suppose now the file gets moved "b/moved", the output of that diff would
then be this:

     diff --git a/b/normal b/b/moved
     similarity index 100%
     rename from b/normal
     rename to b/moved

We prefer the "rename" lines' values in this case (the "diff" line is
always a last resort).  Take note that those lines are not prefixed with
a/ or b/, but the ones in the "diff" line are (just like the ones in
"---" or "+++" lines).