new feature: Adding command aliases

[0xDRRB]

It would be great to be able to define aliases for certain recurring commands, like "alias atr = ]%%[read:33" for smartcards or something like that.

Aliases could be loaded from the MMC in the form of a text file associating a command name to be substituted with a character string. This would be loaded when entering a mode, for example smartcard.aliases loaded when entering smartcard mode.

I'm thinking of something like what I use with my pcscapdu or nfcapdu tools but without being able to use Glib and readline for that (and with much less RAM).