v0.34.0 - Command overhaul

Breaking

Command target change (#535)

Commands: All cmd() methods using custom or overridden targets must use the keyword argument target. This avoids entanglement with inner shell values that include -t for other purposes. These methods include:

• Server.cmd()

• Session.cmd()

• Window.cmd()

• Pane.cmd()

Full Changelog: v0.33.0...v0.34.0