Rewrite of initialization and deinitialization functions

Original code iterates through every possible descriptor in nested
loops and tries to do initialization every iteration without considered
what are those descriptors for nor stopping when interface is finally
claimed. It has following problems:
1. It iterates through all configurations, but explicitly resets a
device configuration to 1 every iteration.
2. It never configures a possibly shared device even it is currently
unconfigured.
3. It treats alternative settings as independent interfaces and iterates
through them while implicitly setting alternative setting to 0.
4. It can claim several interfaces but uses only the last one.
5. It doesn't track claimed interfaces' number and always deinitializes
interface 0.

This in fact works for a device with single configuration, single
interface and no alternative settings, like most of the supported
devices (except G510), but it is fundamentally incorrect. Therefore as
part of migration to libusb 1.0 I've rewritten the initialization
procedure in a more linear way. First it selects a configuration, which
is 1 in most cases. Next it iterates through descriptors in this
configuration to find a single compatible interface. Only after that it
resets the device and claims the interface.

debian/changelog

@@ -3,7 +3,7 @@ libg15 (1.3.0~svn324-2) unstable; urgency=medium
   * Migrate from legacy libusb-0.1 to libusb-1.0 (closes: bug#810409, 
     bug#611649).
 
- -- Alexander Ponyatykh <lazyranma@gmail.com>  Sun, 17 Nov 2019 14:29:55 +0300
+ -- Alexander Ponyatykh <lazyranma@gmail.com>  Mon, 18 Nov 2019 02:44:19 +0300
 
 libg15 (1.3.0~svn324-1) unstable; urgency=medium