By using a for loop, new entries can easily be added to the PATH without
having to enter additional commands. The precedence of the entries can
also be easily adjusted by reordering the list that is iterated over.
The local man pages intalled in /usr/local/share/man should be checked
before the system's man pages for matches, since the tools installed in
/usr/local/bin have precedence over the ones at /bin and /usr/bin.
Change bash history management to ignore consecutive duplicates and
commands starting with a whitespace.