Parsing of db-url parameter breaks if # in any field (specifically, password)

[et304383]

https://github.com/drush-ops/drush/blob/master/includes/sitealias.inc#L1680

Just wasted hours trying to figure this out. Turns out, parse_url doesn't properly handle a URL with a # character contained within.

Drush should handle this since clearly PHP isn't going to fix this.

Tested with Drush 8.1.11 and PHP 5.6

[weitzman]

Maybe drush could preprocess the url to escape the #?

[et304383]

I suspect '@' and ':' would also need to be handled.

[weitzman]

dupe of #1134