Beginning stabs at a Slot#positioning refactoring pulling out methods
Merge branch 'master' into LayouterRefactoring
Adjustments to the height to make code work properly with manual again
More positioning refactoring =) Getting more readable every commit
cleaned up contents_alignment code a bit
The manual works with the positioning refactoring :-D
A last bit of refactoring, really using the Flow and Stack classes

* remove class checks, let Flow and Stack handle that (stack
  always moves elements to new line, while Flow only does so
  if the elements overflow the row)
* Lots of naming changes, especially fot TopHeightData to
  CurrentPosition
* pulled out a lot more methods
Merge branch 'master' into LayouterRefactoring
Specs passing again

* transferred button positioning specs to flow/stack
* for now removed the specs for right_align - need to add
  them back and also implement this
* the tests could probably use some DRYness through shared
  samples
* tests now all use the new outer interface which is just
  contents_alignment not positioning
* oh and common_methods now relies on methods not instance vars
  (cleaner/better)
removed now unused move method from TextBlock (just use the common one)
remove the annoying as hell debug messages when window closes
DRY up specs through shared samples
Specs for contents_alignment and the appropriate stack heights
remove unused right_align_position method
Introduced Constants and changed method name to has_variable_height?

* Constants to highlight the default values e.g. no value
  specified for this slot
* method name change to show that it's only about the height
* not 100% sure if the constants make it clearer
Refactoring to make the variable height more important

* @init_width and @init_height removed now there is only
  @fixed_height
* setup_dimensions from contents_alginment removed, calling it
  once in initialize should be enough
* Constants remvoed as zero and 1.0 are more apparent there and
  only used there which kind of makes it clearer I believe
* some tests added to make sure everything still works (e.g.
  tests that check if the content is bigger and smaller than the
  set height, the height still stays the same)
Merge pull request #399 from PragTob/LayouterRefactoring

Refactoring of Layout/positioning in slot