0.5.2

• New command line interface to the compiler (crystal build ..., crystal run ..., crystal spec, etc.). The default is to compiler and run a program.
• crystal eval without arguments reads from standard input.
• Added preliminar crystal deps command.
• __FILE__, __DIR__ and __LINE__, when used as def default arguments, resolve to the caller location (similar to D and Swift)
• Allow as to determine a type even if the casted value doesn't have a type yet.
• Added is_a? in macros. The check is against an AST node name. For example node.is_a?(HashLiteral).
• Added emit_null property to json_mapping.
• Added converter property to json_mapping.
• Added pp in macros.
• Added to_pretty_json.
• Added really basic CSV.parse.
• Added Regex.escape.
• Added String#scan.
• Added -e switch to spec, to run specs that match a pattern.
• Added --fail-fast swtich to spec.
• Added HTTPClient#basic_auth.
• Added DeclareVar, Def and Arg macro methods.
• Added Time and TimeSpan structs. TimeWithZone will come later.
• Added Array#fill (thanks @exilor).
• Added Array#uniq.
• Optimized File.read_lines.
• Allow any expression inside {% ... %} so that you can intepret code without outputting the result.
• Allow \ at the end of a line.
• Allow using if and unless inside macro expressions.
• Allow marking a fun/def as @[Raises] (useful when a function can potentially raise from a callback).
• Allow procs are now considered @[Raises].
• OAuth2::Client supports getting an access token via authorization code or refresh token.
• Consecutive string literals are automatically concatenated by the parser as long as there is a \ with a newline between them.
• Many bug fixes.