Avoid warning for grouped expression
Avoid warnings for shadowed outer local variable
Avoid warnings for assigned but unused variable
Fix assignment with no effect outside of iterator
Remove trailing whitespace
Liquid has UTF8 support.
Add security tests to show that the symbol table doesn't grow
Remove #to_sym calls from Drop and Variable

Symbols are not needed here and using plain strings is nicer on Ruby
Change Drop method lookup to not hit respond_to?

Class.public_method_defined? ends up diving into Ruby's core looking for
a method with the given method_or_key. This process at some point turns
method_or_key into a Symbol. This change no longer takes that path and
thus doesn't grow the Symbol table.
Convert Strainer to white-list method protection

After moving the method existence check from Context into Strainer,
updated Strainer to only accept invokation methods that were added via
filter Modules, and done in a way that respond_to? is never called,
preventing unconstrained Symbol table growth.
Use sets to check if methods are invokable without symbolizing.
fix `can't convert Fixnum into String`
add tests for replace filter
Add support for filter keyword arguments. Closes #175
Merge branch 'master' into remove-symbolizing

Conflicts:
	lib/liquid/variable.rb
Completely remove unused variable
Merge branch 'remove-symbolizing'
Release 2.5.0
Add reverse filter
Merge branch 'master' into liquid-utf8

Conflicts:
	lib/liquid/variable.rb