bug#24269: 24.5; Add optional arg to `eval-buffer' and `eval-region' to ignore invisible text

[Drew Adams]

Enhancement request.  Add an optional argument to `eval-buffer' and
`eval-region'.  When it is non-nil, ignore text that is invisible.

More generally, maybe: if a (non-nil) symbol, interpret the symbol as a
text property, and ignore any text that has a non-nil value of that
property.

Or if the arg value is a cons (PROP . VALUE), with car a symbol, ignore
any text with property PROP that has value VALUE.

In GNU Emacs 24.5.1 (i686-pc-mingw32)
 of 2015-04-11 on LEG570
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/usr --host=i686-pc-mingw32'