Basic colour theme infrastructure
Colour theme in Idris REPL state

The colour theme is now a part of the REPL state. There's not yet a way for
the user to modify the theme, but the groundwork has been laid.
Merge pull request #476 from david-christiansen/color-repl

Beginning of theming support for REPL colors
Allow colour options from REPL

Add the command :colour or :color. Syntax:

:colour on - enable colors
:colour off - disable colors
:colour TYPE OPTIONS - set a colour

where TYPE is keyword, function, type, implicit, boundvar
amd OPTIONS are ANSI colour names, underline, bold, vivid, dull
Tab completion for setting colours at the REPL
Parser fix for colour setting commands
Colourise REPL prompt
Merge pull request #477 from david-christiansen/color-repl

Set colors at REPL
Add support for init scripts

Now, ~/.idris/repl/init will be run when the REPL starts up. This can be used
to implement colour themes or to set other options.
Update CHANGELOG for init scripts
javascript: positional arguments
Have the REPL save its history between sessions
CHANGELOG update for REPL history
Prevent duplicate dynamic linking

This fixes a bug where :r would stop type providers from working.
Compile Nat as Int, (and plus/mult/fromInteger)

Currently done as a special case transformation - we should provide syntax
eventually so that any desired optimisation can be done as transformations in
patterns/terms.
javascript: prevent name possible name overlap
javascript: fix ffiwrap /HT ihmeckler
Final (I hope!) implementation paper tinkering
SimpleParser: fixed recursive combinators
Merge pull request #478 from david-christiansen/repl-init

Add support for init scripts