Minor change in documentation - `cdr` is an alias for `tail`

Fixes #9
Add totable() and tomap()

Closes #8
Implement method chaining (object-oriented notation)

This patch allow object-oriented notation for all iterators:

    range(10):map(xx):filter(xx):totable()

Generated assembler code has no difference with the original
functional notation. Incompatible API changes:

 * A ``gen`` was wrapped into Lua table in all functions/methods,
   so please do not expect that iter({1, 2, 3}) will return exactly
   same values as ipairs({1, 2, 3})
 * Extra {} braces are no more required for zip, chain, is_prefix_of
 * iter() now supports __pairs and __ipairs on all Lua versions

Thanks for Antal Szabó for the great idea and his initial prototype.
Closes #1
Add a notice about master vs stable branches
Use 1-based indexing for range() generator

Incompatible API changes:

  * range() semantics and default values
Use 1-based indexing for enumerate()

Incompatible API changes:

  * enumerate() now starts from 1
Fix highlighting in doc/intro.rst
Global scope pollution checks included
Review fixes for globals-detector

Closes #11
Fix, local vars instead of polluting global scope
Merge branch 'stable'
Merge remote-tracking branch 'upstream/master'

Conflicts:
	README.md
	fun.lua