ignore object files created in compilation
renamed variables for title regex

The variables used to be called wp_namespace_* which was confusing
because the software is not only useful for Wikipedia and is not only
useful for matching namespaces.
rename variables so regex/regexes is diff_regex/regex

All the code to check for patterns within diff are named regex,
regexes, etc. This is problematic because (a) we already have one more
place we can check for regex and (b) I'm about to about add code to look
for regex in abitrary revisions (/not/ diffs). This change "makes room"
for the next one.
change diff regex options from -n and -r to -N and -R
added code and docs to search for regex within the content of revisions
collapse datetime into a single header

It's already a single field.
remove shannon entropy as something computed

It's really just nothing something most people will use it and it's
somewhat expensive to compute.