#16 vfs::http multiple fixes including directory navigation

[kjnash]

Revise vfs::http so it:
* does glob matching correctly on Apache-style automatically generated directory listings
* correctly converts filenames to and from URLs that have url-encoded characters
* handles servers that do url-encoding with character encodings other than utf-8
* loads package tls on demand if a https:// URL is mounted
* uses per-mount options
* uses a separate module vfs::http::FOO, selected by a Mount option, to analyse directory listings. Thus listings that differ from Apache's automated listings can be handled by a separate drop-in module.
* fixes bugs in unmounting old vfs mounts, and directory detection
* has tests for the new features

The fixes to glob and directory detection allow full directory navigation - even with tk_getOpenFile.

[kjnash]

Patch
1. The attachment is a patch to the current CVS.
2. This also fixes a bug in vfs::http 0.7 and bumps the version to 0.8.
Purpose
1. Browse HTTP directories with tk_getOpenFile
2. Mount and use a transparent teapot repository that is exported by HTTP from another machine.