regex engine - cleanup internal tabs and ws (use -w to ignore)

Having internal tabs causes confusion in diffs and reviews. In the
following patch I will move a lot of code around, creating new files
and they will all be whitespace clean: no trailing whitespace,
tabs expanded to the next tabstop properly, and no trailing empty
lines at the bottom of the file.

This patch prepares for that split, and future splits and changes to
the regex engine by precleaning the main regex engine files with the
same rules.

It should show no changes under '-w'.

Author: demerphq