Merge branch 'master' of https://github.com/edwinb/Idris-dev into windows
Fixing compilation in Mingw32
Ignore windows test binaries
Merge branch 'master' of https://github.com/edwinb/Idris-dev into windows
Allow $TARGET to override libdir on the `idris --install` command.

Some way of installing .ibc files to a location other than datadir using idris --install is necessary for making a system package out of this.
I have a standard script for making an Arch Linux package out of a cabal package up at: https://gist.github.com/4158545

During the build step, it runs:
```
cabal configure --prefix=/usr -O
cabal build
```
and then during the package step:
```
cabal copy --destdir=/tmp/idris/pkg
```
Trouble with the current impl is, that last step calls the Makefile, which calls `idris --install base.ipkg`, which then tries to write into /usr/share/idris-9.5 and gets "Permission denied" errors.
That destdir passed to "cabal copy" is already being passed into the Makefile as destdir/datadir: $TARGET=/tmp/idris/pkg/usr/share/idris-0.9.5.
So this just gives a way of installing idris packages to a location other that datadir, if desired:
TARGET=$HOME/foo idris --install blah
Fully compiles and tests under windows mingw32

Except for feof being a macro in stdio.h, everything pretty much works.
changing the macro of feof to an inline function fixes compilation
Allow type annotations on let tactic
(Experimental) Create deferred definitions by application
Put deferred names in the right namespace
Limited type inference of types in where clauses
Type signatures can now be omitted *only* if the type of the
function can be determined completely from the first call.
Update CHANGELOG
Fix argument names in generated types for where blocks
Tutorial updates
Note on local type inference in 'where', and 'mutual' blocks.
Merge pull request #105 from chetant/windows

Ability to build in Windows MingW32
Merge pull request #104 from LeifW/make_idris_install_respect_target

Allow $TARGET to override libdir on the `idris --install` command.
Change to Util.System for portability
'the' function for inline type annotations
Merge pull request #108 from bitlisp/master

Inline type annotation function
Check result of elaboration at the REPL properly
Undo a change in error rendering that was only for debugging...