If system uptime is less than the duration in the test, thread
will panic due to: 'overflow when subtracting duration from instant'.
Changed duration to 20 seconds to make it unlikely the test will
fail due to this condition.
Since no operations that carry a similar risk of panic occur outside
of the tests, it doesn't seem warranted to depend on an external crate
to fix this.
* Fixing and disabling some tests for windows 10 compatibility.
* Few adjustment for windows in tests (eg bigger timeout for keyserver tests)
* Spaces and temporary single thread ci (to be able to spot the error).
* Update `add_license` script
* run script
* add `remove duplicate lines script` and run it
* Revert changes `English spaces`
* strip whitespaces
* Revert `GPL` in files with `apache/mit license`
* don't append `gpl license` in files with other lic
* Don't append `gpl header` in files with other lic.
* re-ran script
* include c and cpp files too
* remove duplicate header
* rebase nit
* do more validation of imported headers in light client
* generalize informant with traits
* informant implementation for light client
* make comment into TODO
* fix broken test
* disable full checking of headers in light client in sync tests
