For user-generated repos, the default path/URL is .*/fdroid/repo, with
fdroid/ as the root where the 'fdroid' tool operates. This makes for a URL
that is quite unique and easily matched automatically using patterns, like
in fdroidclient.
For those who don't like the standard, they can override the errror from
config.py using nonstandardwebroot = True
Since config.py contains passwords in it, it should be protected as much as
possible. At the very least, the file permissions should be 0600 to
restrict access to user that actually edits and runs 'fdroid' commands.
This tries to auto-detect the SDK and NDK. If it can't find the SDK, it
prompts the user to type in the path. It also tries to find the most
recent version of the build-tools, and should also support the old
unversioned layout.
