To forbid using the comment strings from their inner modes

Closes #4562

And don't block-comment inside a block comment

Closes #4208

Closes #4148

Issue #3941

Issue #2768

Currently, if you perform the uncomment command with the cursor outside a single-line block comment, it will uncomment that block comment. This is unfortunate behavior for cases where the block comment is used to describe the parameter to a function like "foo(/* index */ 0)". It's also inconsistent: if you have a selection and a single-line block comment after the end of the selection, uncomment() will do nothing, however if you have a selection with a single-line block comment *before* the selection, it will line-comment out all the lines of the selection instead.

This also isn't a complete fix, but significantly reduces the scope of the problem. For example if you have "/* foo */ bar /* baz */", uncomment() still does the wrong thing when the cursor is on foo or baz.

Bumping them for every release just adds too much git
noise and history blowup.

Issue #2182

Issue #778

To make sure it isn't seeing comments that are actually
strings.

Issue #1975

Closes #1975

Changes in https://github.com/marijnh/CodeMirror/pull/1731 are missing.

Use it to prevent some unneeded state computation.

(http://stackoverflow.com/questions/16702574/codemirror-comment-js-addon-wont-uncomment-in-ruby-mode)