bring ftp in overview up-to-date

previous one fails to work as intended, OpenBSD's ftp site has changed,
since. This also changes local working
directory to /tmp, just in case.
Escape `*', previously rendered as bad anchor
put commonissues into index, previously missinG
fixed-formatted probably intended here
stylize `before' and `after' property references
stylize delaybeforesend as code, ls as italic
merge old_changes.html into history.rst, closes #19
backport changes from performing diff of 2.3->2.4
Reorder doc index
Exclude byte-compiled files and editor backups from source dist
Bump version numbers for release candidate 2
Make test_sighup robust against a parent process ignoring SIGHUP

Fedora build machines call signal.signal(signal.SIGHUP, signal.SIG_IGN)
as part of daemonizing, but this test needs the child process to use the
default signal handler.
Use PYTHONIOENCODING=utf-8 for tests.

Closes gh-22
Bump version numbers for release candidate 3
Bump version numbers for 3.0 final release
Fix Trove classifiers to allow PyPI upload
Added a control arguments to pxssh login method
- key verification for localhost
- configurable quiet setting
- synchronization multiplier for (very) slow connections

Added new method (try_read_prompt) to pxssh for performing the prompt read
quickly on fast connections while not failing on slower connections
Remove unhelpful examples
Merge pull request #26 from takluyver/examples-cleanup-1

Remove unhelpful examples
Cleaned up prompt synchronization