fix port interpretation for ssh/gsissh URLs
Fixes issue #58
Fixes #52
more work on tutorial
started working on mandelbrot example
mandelbrot
fix password prompt response
fix prompt detection -- dash does not support nelwine in PS1
fix signature for dir.get_size ()
add size property to dir
fix get_size for directories, POSIX compliant
adapt code example
Merge branch 'devel' of github.com:saga-project/saga-python into devel
also fix du for file size (use 'wc -c')
fix logic on file staging
add purge_on_start
add simple signature test
more documentation work... ugh.
working mandelbrot tutorial example
Support for protected ssh keys, better default context detection, fix shell bootstrap

This commit fixes #66, and resolves a coupld of related issues with ssh context
handling.  Tested with various ssh key types, but additional tests would be
appreciated.