Fixed Bug#428274 make_sandbox fails on Mac OSX 10.6 "snow Leopard"
Increased starting timeout from 20 to 60, because some recent versions of MySQL are quite slower to start.
Added a dedicated history file per each sandbox (Thanks to Gerardo Narvaja for suggesting it)
fixed bug in make_sandbox when dealing with a non-standard answer to the "which" Unix utility
added error checking for 'bash' to low_level_make_sandbox
improved error checking for mysql_install_db script
renamed 'sandbox' tool -> 'msandbox' to prevent clash with existing tool in Linux distros
Added "--no_run" option to low_level_make_sandbox, to stop the server when using the "--load_grants" option. The purpose is to end the command without leaving any running sub-process.