Help output in debugger is misleading (registers should be regs)

[r2p2]

When calling help within the debugger, we get the following output.

> help
...
= Debug Information
registers            Print a dump of the CPU registers
flags                Print a dump of the CPU flags
....

But the command to print a dump of the registers seems to be just regs.

[jgilchrist]

Thanks @r2p2, you're absolutely right! I've fixed this in a5c5c18.