Use binary search to determine what tokens are keywords
Remove EXPAND_SKIP_PROCESS, which did not actually work
Unescape strings in keyword detection.

This allows keywords to be quoted. However, they may not contain
variable or process expansions, etc. Fixes #1398
ls: find and use various dircolors initialisation files, if they exist

Closes #1758.
web_config: map nonexistent post requests to 404
web_config: add support for adding and editing abbreviations

Possible future enhancements include explanatory text and an image for
the 'save' action.

Work on #731.
Allow funced to retry on error

Fixes #1371