RAT_EVENT()    Event handler - inkey() with mouse awareness
 RAT_ERBHD()    Determines if right mouse button is held down
 RAT_ISMOUSE()  Determines mouse usage by RAT_EVENT()
 RAT_ELBHD()    Determines if left mouse button is held down
 RAT_EQMCOL()   Returns mouse column at last press
 RAT_EQMROW()   Returns mouse row at last press
 IFMOUSEHD()    Checks if mouse held down,evals codeblock while it is
 ISMOUSEAT()    Checks for mouse click within passed coordinates
 MBRZCLICK()    Checks for mouse click on current Tbrowse row/col
 MBRZMOVE()     Checks for mouse click at and moves to Tbrowse row/col
 MOUSEHOTAT()   Checks for mouse click from array of hot coordinates
 RAT_LASTEV()   Returns the last event recorded by RAT_EVENT()
 R_ISRATREAD()  Determines if RAT_READ() is current get system