Add MashApe button to README.
Revert "Add MashApe button to README."

This reverts commit 2cf348ff98a7096cee20a6ea698f8dcd569a697d.
added support for mnemonics and omitting the 'use' command
added tests for shortcuts, and removed candidates in place of commands
Some tweaks on mnemonics specification.
Made mnemonics more concise.
Offline mode asserted in help specification.
Further mnemonic tweaks.
Update help to reflect new mnemonics.
Up version to 1.2.0
Fix errors in help text.
Fix zsh double shift bug and cleaned up main gvm function code.
Fix selfupdate bug.
Added mnemonic i for install.
Added mnemonic b for broadcast.