Adding macros with attributes using separators (|) in rich text (WYSIWYG) breaks

When adding a new macro through the RTE, all pipes (|) are escaped.

For example:

{toc:type=flat|separator=pipe|maxLevel=2}

becomes

{toc:type=flat\|separator=pipe\|maxLevel=2}

This bug does NOT:

1. Escape existing macros on pages
2. Escape macros added through wiki markup

This is because, when a macro is initially added it is parsed by the renderer as text rather than as a macro (it needs to be surrounded by a macro div).