Fixed: moved the "can't cast to T because it was never instantiated" error from compile-time to runtime

[Hashes] Adds a comparator and changes the initializers a bit

Fixed #349: Crystal always produces ELF 64-bit object files. Use target triple to create LLVM::Target (was using the first one available). Thanks @jhass for finding this!

Fixed #346: Heredoc is not respected in line number calculation. And some other fixes and specs related to heredoc.

Renames LocalDependency to PathDependency

Adds support for local dependencies in Projectfile

[Specs] Adds convenience method context

Add limit to all String#split variants

Context does the same as describe, but is more semantic on some contexts
(no pun intended).

Adds the IndifferentAccessComparator, that allows to also use symbols as
keys, even when the Hash was created with Strings as keys.

The default value in the actual initialize method was not being used at
all (probably a left over), so I remove it. I also added a few other
ways to initialize hashes, so that you most likely will be able to
initialize it any way you want without having to pass nils, just to
comply with the arity.

[String] Adds size method for strings

This is something ruby supports and probaly the most used method to find
the length of a string.

RNG namespace for number generators

Random::ISAAC pseudo random number generator

Enables to select an engine for Random. The Engine may be
initialized with a seed and must respond to #next_number

Removed Random#srand and other srand methods that don't work
anymore (one may seed the Engine instead).

Added conway and wordcount to examples (based on http://arthurtw.github.io/2015/01/12/quick-comparison-nim-vs-rust.html )