Replicant

• That can easily be remembered, without needing any Internet access or a computer nearby. You might be far from home, without Internet and without a computer when you need to switch back the modem on, or switch it off in a hurry.
• That is easy enough to type without any mistake, with the default keyboard in the default console.

In addition to the rename, and the update of the parts that mention the script name in the build system (such as in vendor/replicant and in Android.mk), we also need to pick up the new name in the documentation.

edit: fix copy-paste mistake.

This should be done now.