Wiki Edits: adding Richard's comment about mach's memory management issues

[Joshua Branson]

Richard mentioned this issue a few days ago regarding tmpfs changes.  I
am adding it to the wiki under open issues/gnumach memory management.

I also removed the link to the FOSS bounty.  It looks like that bounty
has been paid already?  Perhaps we should keep the link open in case
someone wants to contribute more money to it?

Also, I discovered that we have 3 pages on gnumach memory management.

https://www.gnu.org/software/hurd/microkernel/mach/gnumach/memory_management.html

https://www.gnu.org/software/hurd/open_issues/gnumach_memory_management.html

https://www.gnu.org/software/hurd/open_issues/gnumach_memory_management_2.html

The first two are probably outdated, and I could try to update them in a bit.
And I should probably combine the two open issues memory management pages...

0001-I-am-adding-Richard-s-comment-about-mach-s-memory-ma.patch
Description: tmpfs and memory management

Thanks,

Joshua