Feature/remember last position of cursor inside previous window

[juarezr]

Current behavior

• After a window receives focus, the extension:
  • Checks if the cursor already is inside the window
  • When the cursor isn't then it moves the cursor to the center of that window.
  • Otherwise, it doesn't change the cursor position.

Proposed behavior

• After a window receives focus, the extension:
  • Checks if the cursor already is inside the window.
  • Checks if it has the last cursor position inside the window.
  • If positive then it doesn't change the cursor position
  • Otherwise:
  • When it has the last cursor position then it moves the cursor to this position.
  • Otherwise, it moves the cursor to the center of that window.

Advantages

The last position when compared with window center positioning has the following advantages:

• It's a better guess of what would be the shortest path from the cursor position to the next click position.
• It considers users' intentions for cursor placement.
• It keeps the same advantages of the previous approach.

Disavantages

• It could raise involuntary click incident rates as it puts often the cursor near the last clicked widget.
• Sometimes users prefer fixed positions.
• The center of the window is the shortest distance to all points inside the window, thus being better positioned for fast movement.
  • However, mouse clicks tend to concentrate on some hot spots instead of being linearly distributed through the window.

[xalt7x]

@LeonMatthes , Any chance of merging? This patch series greatly improves usability and probably closes #7 .