v0.7.6-alpha — your own master password, terminal mouse fixes, quit confirmation

New

Your own master password. Stored passwords are encrypted with mRemoteNG's default
passphrase, which is public — anyone holding a confCons.xml can read every credential in
it. You can now set your own from Settings, and files already protected with one finally
open: the app asks for the passphrase and can remember it in the login keychain.

Changing it re-encrypts every stored password and rebuilds the root marker the way
mRemoteNG writes it, so Windows keeps reading the file and asks for the same passphrase.
Setting it back to the default removes the protection.

The open configuration file is shown in the title bar — the proxy icon's Cmd-click menu
gives the full folder path, and the folder is spelled out in the window subtitle. Useful
when several confCons.xml files live in different directories.

Fixed

The mouse wheel did nothing in mc, less and vim (#6). Those run on the terminal's
alternate screen, which has no scrollback to scroll — so the wheel was silently inert and
Page Down was the only way through a file. It now sends cursor keys there. Ordinary shell
sessions still scroll the scrollback as before.

Text could not be selected while a program was using the mouse (#6). With mouse
reporting on, every click went to the remote side with no exception, so in Midnight
Commander the mouse only ever drove mc. Holding Shift now suspends reporting for that drag,
which is the usual way out in a terminal.

Cmd+Q quit instantly (#8) — one key away from Cmd+W. It now asks when connections are
open or the configuration has unsaved changes, with a Save and quit option in the latter
case. With nothing to lose it still quits straight away.