[DOC] Truncated contribution mini-guide pointing to new location
[FEATURE] Storage of custom variables on FormComponents

This allows a "variables" property to be used on every Form component and ViewHelper. Setting an array of variables here, makes those variables available anywhere the Form object is available.

Can, for example, be used to store custom rendering instructions for the Preview section as described in #411
Merge pull request #412 from NamelessCoder/componentdatastore

[FEATURE] Data storage on Form components and ViewHelpers
[BUGFIX] Proper fetching of configured plugins in ControllerActions component
[BUGFIX] Incorrect check for existing class
[FEATURE] Add a reset() method to Providers

Method flushes internal caches completely but can be overridden to perform other actions. Currently not called by our code.
[TASK] Minify clear cache command
[TASK] Remove an unused variable
[BUGFIX] Clear field behavior not respected
[TASK] Refactor ContentProvider to ease test coverage
[TASK] Remove 4.x sheet title support
[BUGFIX] Sheet getFields can return ContainerInterface, should be FieldContainerInterface
[TASK] Let FieldContainerInterface extend ContainerInterface
[TASK] Minify a condition in getMergedConfiguration
[TASK] Do not permanently prevent Providers if registered then unregistered
[TASK] Test coverage of all PR code, increased coverage
[TASK] Let RecursiveArrayUtility cast arguments to array
Merge pull request #413 from NamelessCoder/coverage

[TASK] Quite a few minor tweaks and fixes - and test coverage to 98% of all classes
[BUGFIX] Allow Section and Container to be returned from getFields()
[TASK] Clean up some conditions for legibility