Change filename in ruby bindings

More documentation for ruby bindings

Readme links

Custom printers for user token types

I did this in a hurry, but it appears to work locally. I tested it with
a couple boring custom token type printers.

Fix clobbered variable warning in regex.c:run_trace. Fixes #162

linked more documentation/resources

travis cert issue fix

build on Windows with scons

This will guarantee we can build hammer with default arguments

To homogenize the file and allow keys/strings to be searched easily.

We disable:
- the tests (which require glib) although they can be
  reactivated with the `--tests` command line flag
- shared library (lack of export symbol declarations
  means that although it can be built, no symbol is
  exported and therefore it can't be used)

The `install` target installs the library and headers
under the `build` folder, because it's a traditional practice
to move libraries to a central location on Windows, unless
you are using cygwin. In which case pass `prefix` to the
command line.

We adapt tools\windows\build_examples.bat to take the library
that is built using scons or using tools\windows\build.bat

We will need to use the environment's CC variable to make decisions
that apply to windows compiling and linking. Therefore we move some
existing sections below the set up of env["CC"] and env["CXX"]

Finish porting parsers to windows

This is proof that Hammer can be linked and used in a windows
program!

We port registry by importing the (public domain) openbsd implementation
of the tfind/tsearch POSIX binary tree search functions.

These are only necessary when building on non-posix platforms

MSVC was complaining that the `tail` variable was potentially
uninitialized in the while branch. Since the while loop is actually
coupled to the if (head != NULL) that initializes the tail variable,
we move them together, which makes the warning disappear.

The last file to port for the library is registry.c

As MSVC doesn't implement C99, variable-length arrays
are not supported. We use _alloca instead.

It is the counterpart to c4018 for x64 compilations.