javascript: added foldJS
Automatically detect console width

This can now be overridden with the :consolewidth command at the REPL or
in an init script.
Correctly pretty-print no-argument Nil

Previously, when the Nil constructor took no arguments (as was the case
with HVect), it was not shown in sugared syntax in the pretty-printer.

Fixes #820.
javascript: refactor inliner
Add --repl [package] command line option

Checks the package, then starts a REPL using the main module listed in
the package description. If no main module is given, the REPL is not
started.

(This means library packages will need a main module listed --- it has
no other effect that to be the 'home' file for the REPL).
Added Functor, Applicative, and Monad Provider instances
javascript: make use of inliner
Merge pull request #834 from david-christiansen/semantic-pprint

Automatically detect console width + fix pretty-printing of no-argument Nil constructors
javascript: inline more constructors
javascript: inline simple functions
javascript: remove redundant continuations
javascript: JSNull is a constant
javascript: inline more functions
javascript: inline more functions
Merge pull request #836 from trillioneyes/monad-providers

Added Functor, Applicative, and Monad Provider instances
Fix display of CantConvert
Better emulation of C in executor wrt file handles

Now, we return a null pointer on failure to open a file, and we allow
isNull to check handles as well as pointers. For handles, it returns true.
Better emulation of C in executor wrt file handles

Now, we return a null pointer on failure to open a file, and we allow
isNull to check handles as well as pointers. For handles, it returns true.
Minor tweak to pretty-printing lambda

Indent the body of the lambda slightly
Use pretty-printer to show the result of :x