[spec] Update summary
[spec] Update requires

Also do not call find-requires and find-provides on shared libraries.
Tarball should be mostly self-contained (i.e. it bundles everything) and
some of the required symbols will be satisfied later, when user decides
to install Android NDK, ...
[spec] Drop chrpath

This shouldn't be needed (?)
[spec] Add forgotten BR: desktop-file-utils
[spec] Simplify desktop file installation a bit
[spec] Move everything to /opt
[spec] Formatting
Merge pull request #1 from msrb/spec-tweaks

spec file tweaks