Update reference/constraints/Image.rst

Seems that annotations do not support trailing commas in parameter lists like PHP arrays do.
Added failure_path param
Created introduction and toctrees
Created DialogHelper documentation
[WIP] FormatterHelper docs
[Config] Fixing up most of the Configuration examples for (mostly) missing children nodes - special thanks to @pierswarmers for pointing this out
Changed wrong argument names in Twig
As twig will support named arguments soon
fix comment to describe the sample code correctly
add "hasser" tip for boolean getters
fixed issue:1943 a typo
Removed 2.0 only functions
Added new functions
Added Tests
Added humanize filter
Added versionadded blocks
Added cookbook article about console logging
[Security] add description and example for the special ROLE_PREVIOUS_ADMIN role
added Stopwatch component documentation
Changed normal link to special :phpfunction: link
Changed normal link to special :phpfunction: link