Updated build target to correct file permissions

https://lintian.debian.org/tags/control-file-has-bad-permissions.html
https://lintian.debian.org/tags/non-standard-dir-perm.html
https://lintian.debian.org/tags/non-standard-file-perm.html
https://lintian.debian.org/tags/non-standard-executable-perm.html
Moved libraries to /usr/lib and includes to /usr/includes (previously under /usr/local)

https://lintian.debian.org/tags/dir-in-usr-local.html
https://lintian.debian.org/tags/file-in-usr-local.html
https://lintian.debian.org/tags/file-in-unusual-dir.html
Added check target to Makefile
Corrected libdir in .la files

https://lintian.debian.org/tags/incorrect-libdir-in-la-file.html
Removed executable bit from .la files

https://lintian.debian.org/tags/executable-not-elf-or-script.html
Removed executable bit from shared libraries

https://lintian.debian.org/tags/shlib-with-executable-bit.html
Removed duplicate copies of shared libraries

https://lintian.debian.org/tags/ldconfig-symlink-is-not-a-symlink.html
https://lintian.debian.org/tags/ldconfig-symlink-missing-for-shlib.html
Added built artefact to .gitignore (finally!)
Added copyright file

https://lintian.debian.org/tags/no-copyright-file.html
Added maintainer scripts to call ldconfig

https://lintian.debian.org/tags/postinst-must-call-ldconfig.html