Merged screen bars into one array
New feature, bars can be stacked next to each other

Enables user to create many bars in the same position
For example 3 bars on the top, every bar will be rendered under previous one
Positions can be mixed, bars will be placed and sized according to available space dictated by order of bars in the bars list
Fixed _NET_WM_STRUT handling

Bars are pushed away from the edge if client requests space
New feature, floating bars
Rendering widgets in proper position, added Even layout
Proper font size calculation

Now font size is calculated to fit text in a container respecting both width and height
User can specify fixed width and if text will be changed during execution, font size will be matched to container dimensions
Refactored TextBox padding

Now user can pass padding value in kwargs
Value must be one of the following:
    - integer: all sides will be set to passed value
    - tuple: sides will be set in top, right, bottom, left manner (clockwise)
      if tuple length is less than 4 zeros will be appended

If user specify fixed font size bigger than available area with padding applied
font size will decreased to fit the whole string inside
New feature, horizontal and vertical text-align

User can import alignments from widget.base and pass align and valign in kwargs

All alignments are including padding and working with both fixed and calculated font size
Refactored clock widget
Added Fixed layout
Pre-adapted some of the widgets
Enabled mouse button handling
Changed Configurable class

It makes more sense to assign real attributes once
instead of searching for proper value every time attribute is requested
If given attribute has a setter then it will be used
Removed redundant assignments
Naming changes, refactored padding
Broke excessive lines
Adapted Image widget
Merged redundant Textbox class
Added constant module
Corrected children size calculation logic