Improve README. Add groups for key mappings.

Also, clarify Ruby bindings info a bit.
Improve closing description
Add more support for GVim and Vim 7.3

Closes #4. Adds guitablabel function, provides better default colors for
GVim. Also changes the tab moving implementation to let it work in (G)Vim
7.3 too.
Add tab copying (Y)

By pressing Y the current tab is copied (with its buffer list,
jump list, and search history). The layout and visible buffers are not
preserved currently.
Load the last buffer in the tab copy
Add more explanations for tab management
Fix README wording
Reformat README
Add Esc key. Closes #7
Fix README
Block unnecessary escape sequences
Add Esc to Nop mode
Change unnecessary redraw! to redraws

Connected with issue #9
Add Vim help

Closes issue #5
ignore tags (created by :Helptags when using pathogen
Move names creation to Ruby if available

Connected with issue #10
Merge pull request #11 from montefra/ignore_tags

ignore tags (created by `:Helptags` when using pathogen)
Merge branch 'master' of github.com:szw/vim-ctrlspace
Update graphics
Improve README