Version 0.1.4: Fixes and extension functions

Language extensions:

• Added the experimental module, with the group-by macro
• Added the is-decimal and is-integer functions (PR #27 by @ecerulm)

API extensions:

• Support for named modules

Bug fixes:

• Handle long number literals in JSLT source code
• Fix NPE in JsltException
• Fix NPE on object matcher inside declared function