Unit tests for issue #430.
Merge branch 'master' into issue_430_lap_2
Add some blank lines in `testAfterEnterInEmptyLi`.
Fix indentation.
Fix code style.
Fix code comment style.
Merge branch 'master' into issue_430_lap_2
Merge branch 'master' into issue_430_lap_2
Merge branch 'master' into issue_430_lap_2
`pOrDivAfterEnterInEmptyLi` tests: updates and fixes.
New methods: `.isBlockNode` and `.isListNode`.
`isInlineNode`: Fix; text is in-line as well, of course.
`.setCaretBefore`: Can set caret to a `br` that has before it any block.
Issue #430: Added test for the invalid list nesting case.
Issue #430: Handle gracefully in all browsers.
`enterInEmptyLi` tests: Data structure change.
`enterInEmptyLiTest`: Fix caret testing.
`WYMeditor.CHARS.NBSP`: Introduced and implemented.
Merge branch 'master' into issue_430_lap_2
Issue #430 handling overhaul.