Signed-off-by: Adam Crowder <adam@adamcrowder.net>

While GNU mktemp will handle any number of X's, busybox mktemp (used in Android/Termux and distros like Alpine) insists on exactly 6 of them.

* implements log option

* dockerfile: use multistage build, add dockerfile to ignore

* gdrive: supports only oauth 2.0 client id json file for now

Fish alias/function example shown for using wget in the Readme uses Bash-style command substitution (with $) rather than Fish-style (no $) and will throw an error when used.

* Head handlers & Update README.md

* GDrive provider support
* More reliable basedir ownership
* Fix mimetype

Added a section that explains how to get the `transfer` alias on Windows.