Fix build

Added missing jars, removed wrong or duplicate jars. Updated build script to
copy all jars.
Minor adjustments to ssh2 support

Get rid of some debugging distractions in stream handling.
Removed some debugging code from ssh2 connector.
Added .gitignore
Added IntelliJ files to gitignore
Updated ssh2 connector to use pcells subsystem channel rather than $BINARY$ mode
Adapt gitignore to ignore dist