Fix up tests to run again from the browser
Implements browser visibility API

Fixes #14
Mute sound when stoppd. Fixes #15
* added ?autochain and ?autorun (for tapes)
* moved keyboard constants to utils
* add "rewind tape" option
Disable keyboard during autoboot/chain/run
Merge pull request #17 from murkle/master

?autochain and ?autorun (for tapes)
add Master 128 numeric keypad (plus other small keyboard tidying)
Merge pull request #20 from murkle/master

add Master 128 numeric keypad (plus other small keyboard tidying)
Reformatting, tweaks to autochain and autorun
Automatically handle same key twice for autotype
Reinstate the suspend-on-focus, this time with support for letting tapes load in the background still. Fixes #14 (again :))
Embarrasingly small change to fix Zalaga's use of undefined opcode 0x7c
Reinstate sound muting
Clear up some keyboard autotype issues I'd introduced
Support ANC. Gets Repton 2 working. c.f. issue #5
Stupid braino in master nmos
Implement all the remaining 'undefined' opcodes. Probably incorrectly...but...  Fixes #5
Testing webhooks
End of webhook testing (maybe)). bbc.godbolt.org/beta should auto-update on checkins
Stop robots from crawling the beta site