Added data options
Documented the Chars module and added new functions.

+ ord and chr
+ isOctDigit
Switch on 'elabPE'

Generates a new specialised definition for [static] argument positions
which are then elaborated recursively.

Not yet transforming from the original call to the specialised
definition. Also still need to take more care in how we specialise
definitions - however, the mechanics of generating the new definitions
is now done.

Generating new definitions may fail for various reasons (scoping errors,
for example). This is considered safe, and just fails silently, because
it just means it's not a specialisable call.

Also removed the {static} syntax because it's inconsistent. [static]
only works on named pi bindings due to awkwardness in the parser.
Support for the new interactive commands via the IdeSlave REPL
Also, add ":addmissing" and ":addmissing!" to completions of the REPL

fixes #668
Eliminators working for some type - still experimental. Will create a way to make them work with the elim type class
When specialising, reduce more names

Specifically, all names which are called by the function being
specialised, by searching the call graph.

(Maybe we should also reduce inlinable names)
Added a --nobanner flag to supress the banner.
Fix enumFromTo for Nat, Int, and Integer
Make sure deferred definitions get totality checked

Fixes #677. Now deferred definitions are all checked at the end of
checking a module.

Also, a minor fix for the situation where a function had no descending
or same arguments, which was getting ignored.
Added support for more char primitives.
Partial support for Integral Classes.

Added a simple Integral Class to Classes supporting:

+ div
+ mod

toInteger and other suitable methods need to be decided upon, defined, and implemented.

Instances:

+ Nat uses total functiond
+ Int, Integer, Bits8-64 are partial.
Fixed testing failures I accidentally introduced when showing a better naming for machine generated names (so that I could better debug)
Totality checker improvements (soundness)

When spotting a cycle, need to check that the decreasing argument
is in the same position.

For the moment, this means we can't spot decreasing arguments which
change position across multiple calls - but soundness is more
important!
Merge pull request #676 from markuspf/fix-enum

Fix enumFromTo for Nat, Int, and Integer
Merge pull request #672 from hannesm/fix-668

Support for the new interactive commands via the IdeSlave REPL
Merge pull request #679 from jfdm/prelude/chars

Changes to Prelude.Char
Merge pull request #680 from jfdm/prelude/integrals

Partial support for Integrals.
Merge pull request #675 from cgswords/master

[Issue 590] Added a --nobanner flag to supress the banner
Distribute travis builds.
Add some system-level ghc packages.