Improved bind mount based test script

Rather then overwriting the installed themes (which is slow and somewhat
destructive), this script simply bind mounts the theme directory over
the relevant mountpoint, then waits for the user to hit a key to unbind
it.

This makes testing fast, safe and easy.
Added chrome.rc to fix Google Chrome window borders.

Using Mint-X, the Google-Chrome window borders incorrectly picked up the
theme_selected_bg_color, which makes them stand harshly against the
window borders. This customization file corrects this to display as a
matte-grey.
Adds chrome.rc to the include directives in gtkrc.
Merge pull request #20 from wrouesnel/improve-test-script

Improved bind mount based test script
Merge pull request #21 from wrouesnel/chrome-fixes

Google chrome fixes
Centralized theme coloring changes.

All text (normal and selected) is rendered as #2c2c2c. Restored the
original selected_bg_color to #accd8a.

Re-ordered "settings" lines for easier maintenance.