Allow user to add new print directives defined with macro 'define-rule'
Use correct slot accessor of 'print-command'
Small refactoring

Rename add-print-directive to register-print-directive
Make *user-print-directives* internal in closure-template.parser
Create a unique symbol for each new directive
Don't wrap directive parameters in list when making all print directives handler
Syntax fix in print directive registering
Fix print directives accessing
Divide print directive adding in two steps + remove supplementary rule defined by user
Allow user to add new print directives defined with macro 'define-rule'
Use correct slot accessor of 'print-command'
Small refactoring

Rename add-print-directive to register-print-directive
Make *user-print-directives* internal in closure-template.parser
Create a unique symbol for each new directive
Don't wrap directive parameters in list when making all print directives handler
Update sample output and add RequireJS sample
Fix issue with interning symbol
Fix warning about implicitly defined generic function "compile-template"
Get latest changes in custom print directives
Small refactor on new custom print directives.

More work is required including fixes for FIXME comments.
Implement custom print directives for Javascript backend

Use user symbol to identify data after parsing
Existing issues:
1. Order of print directives application may be reversed.
2. RequireJS backend is not supported.
Fix order of custom directives in Javascript
Use handler names (not functions) properly in Javascript backend
Use new Javascript modules format
Add custom directive support to RequireJS backend

Additional parameter is added REGISTER-PRINT-HANDLER - :MODULE.
It is usefull when actual function implementation is loaded via RequireJS
too and contains URI for module containing functin :FUNCTION.
As javascript backend, implementation can be specified via :HANDLER argument.
To handle directive parameters :PARAMETER-CONVERTER must be used.
Merge remote branch 'archimag/master' into print-directives