{% extends someVar %} support.
Added the option to use context vars when using the `extends` tag.
Adding tests for using extends with context vars
Fixing syntax to correct lint errors
Added indent parameter to json_encode filter to support pretty-printing.
Merge pull request #98 from digitalbazaar/master

indent parameter for json_encode method
Merge pull request #95 from gigafied/master

{% extends someVar %} support.
Tell user which arguments were sent to tag
if tag: avoid leaking __keys variable into global scope
Merge pull request #110 from apiaryio/fix-for-leak

if tag: avoid leaking __keys variable into global scope
Merge pull request #108 from apiaryio/improved-tag-reporting

Tell developer which arguments were sent to tag
Autoescape uses true/false, not off/on
Merge pull request #112 from apiaryio/autoescape-documentation-fix

Autoescape uses true/false, not off/on
adding contributing doc
fix compile errors
fix compile one more error, extends define needs brackets
Merge pull request #121 from stanislavfeldman/master

Fix errors in some browsers such Android
version bump 0.12.1
make uniform quotes
- Added support for object keys containing dots,
     e.g. obj["hello.there"]
- Fixed a trailing space bug when invoking macro with variable as last parameter and trailing space,
     e.g. {{ somemacro( "hello", person.name ) }}
- Added test cases
Fixed lint issues, removed username from comment