Updated whitespace control

This release comes with a much more solid implementation for the whitespace control. Kudos to @funkjedi!

Not exposing $_SERVER anymore

Fixes #114. This issue is particularly important because $_SERVER may contain sensitive data, like AWS access keys, which then can be accessed from user-provided templates.

To re-enable old unsafe behavior, use:

Liquid::set('EXPOSE_SERVER', true);

Content ticks

#113: Content ticks allow us to track the rendering cost at runtime, abort it or do something else if a template takes too much time to render. (Kudos to @timglabisch!)

Bugfix release

• Filterbank shall now ignore use of __construct as a filter (by @PATROMO)

Whitespace control for tags

• Whitespace control implemented for tags (see #109).
• Strings now have a 'size' property, for a number of characters.

Bugfix release

• Now we return null for missing properties, like we do for missing keys for arrays. (#101)

Paginate tag gets updated

• Paginate tag shall now respect request parameters.
• It is now possible to set a custom query param for the paginate tag.
• Page number will now never go overboard.

Major thanks to @edwardoka and @asacarter.

Bugfix release

• TagPaginate shall not pollute the global scope, but work in own scope. (Thanks @edwardoka and @asacarter)
• TagPaginate errors if no collection present instead of vague warning.

Bugfix release

Now a capture tag will save a variable in the global context. (Fixes #90)

Bugfix release

• TagUnless is an inverted TagIf: simplified implementation
• Allow dashes in filenames (thanks @j-angnoe)