One-gadget

* Make one_gadget as library (47)
* Fix circular require (707aeb7)

* Show descriptive error message when encounter unintended usage (38, 40)
* Improved update checking (42, 43)

* Upgrade lots of things
* Add `--info BuildID` option
* Add builds of 32/64 libc(s) on Ubuntu 17.10 and 18.04
* Add XMM instructions: `movq/movaps/movhps`

* Find gadgets with less constraints!

* fix relaxations call and jmp (12, 14)
* add updater (13)

* The relative offset in 32bits libc should be GOT instead of rw-p segment
* Add new libc(s) of ubuntu 16.04/17.04 to builds
* When build id is not found in database show warning message instead of nothing