* README.md: Update readme to include mark-next-like-this symbol
* features/step-definitions/multiple-cursors-steps.el: Add phrase for
mark-next-like-this-symbol
* features/support/env.el: Add keyboard shortcut for
mark-next-like-this-symbol and fix shortcut for
mark-next-like-this-word
* mc-mark-more.el: Add mc/mark-next-like-this-symbol function
* multiple-cursors-core.el: Add mc/mark-next-like-this-symbol to
functions to run only once
* multiple-cursors.el: Add to readme section.
* README.md: Add mc/mark-next-like-this-word tidbits to readme.
* features/step-definitions/multiple-cursors-steps.el: Add
mc/mark-next-like-this-word call.
* features/support/env.el: Add shortcut for mc/mark-next-like-this-word
as "C-S-c C->".
* mc-mark-more.el: Add to mc/mark-next-like-this description to explain
what happens when no region is selected. Add
mc/mark-next-like-this-word function.
* multiple-cursors-core.el: Add mc/mark-next-like-this-word to commands
to run once.
* multiple-cursors.el: Add information about mc/mark-next-like-this-word.
