weston: bump version to 1.7.0

- Bump version to 1.7.0
- Add a hash file

libinput is now a required dependency:

configure: WARNING: unrecognized options: --disable-libinput-backend

checking for LIBINPUT_BACKEND... no
configure: error: Package requirements (libinput >= 0.8.0) were not met:

Package libinput was not found in the pkg-config search path.
Perhaps you should add the directory containing `libinput.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libinput' found

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>