add get/set for FastThreshold

[wugulabs]

#1597

This pullrequest changes

Extend the interface of the ORB class by adding a getter and setter for the FastThreshold parameter

force_builders=Custom
buildworker:Custom=linux-1,linux-2,linux-4
docker_image:Custom=ubuntu-cuda:16.04

[wugulabs]

Although I just expose two additional functions, 1 test fails in Linux x64 (all other plaforrms build fine), namely:

• Face/MACE_.salted/1, where GetParam() = ("dudek")

This failure is unrelated to the (small) changes made by this PR.
How to continue from here?

[berak]

hello @wugulabs ,

This failure is unrelated to the (small) changes made by this PR.

indeed, not your fault. sporadic test failure, i'll look into making it more robust.

How to continue from here?

maybe just wait. the next rebuild will probably fix it.

[alalek]

Thank you for contribution!