This patch forces write_file_if_contents_differ/2 to use raw bytes as
when writing files. This fixes an issue where UTF-8 characters are
processed and written back as ISO-8859-1 into the file, which makes it
impossible to use UTF-8 characters in .app.src files.

Instead fetching and resolving src deps (which could depend on pkg deps)
and then pkg deps this patch combines the two into a single set of
iterations by level. The only difference between src and pkg deps in this
new install_deps is how their deps list is found -- from the config or
lock file for src deps and from the neighbors of the vertex for pkg.

Changes parse_git url function to use Using RFC3986 standard to validate
git uri instead of matching strings in function head. Also accepts scp
style syntax for parsing.

`template` is not a kv-style argument, but a plain argument. If you give `template=app` on the command line, you get "template not found."