Merge luckyhacky's PR to automate build of tincd binary for ARM.

Reviewed makefile to have better dependency tree and avoid many if/else
blocks.
Use latest OpenSSL and disable PIE to avoid re-occurrence of issue #9.

This should close #7.
Implement auto start on boot feature.

Can be activated via a new preference.
Closes #2.
Add force reconnection on network state change feature.

Closes #10.
Merge remote-tracking branch 'linux/master'
Bump ant target to coincide with AndroidManifest.xml
Better .gitignore
Include tinc as a submodule, version 1.0.23
Add openssl as submodule at version 1.0.1f
Don't download the ndk ourselves
Create res/raw dir
Use tinc master for compilation (as done for previous releases of tinc GUI).
Improve Makefile for sub-modules.

Automatically init/update submodules from Makefile. Better mrproper.
Improve documentation.