Keep original login during the session

Add:
 - starter: the session initiator (AKA login).
 - euid
 - gid: only primary group.
 - egid

This is useful to track action even after a user change (such as su or
sudo).

For a much simpler analysis, numerical IDs are resolved to their actual
text values.

log examples:

user@host:~ $ ls
Jan  9 00:37:12 host snoopy[1071]: [starter:user, uid:user euid:user gid:user egid:user sid:1069 tty:/dev/pts/1 cwd:/home/user filename:/bin/ls]: ls

user@host:~ $ sudo ls
Jan  9 00:38:30 dhcp snoopy[1072]: [starter:user, uid:user euid:user gid:user egid:user sid:1069 tty:/dev/pts/1 cwd:/home/user filename:/usr/bin/sudo]: sudo ls
Jan  9 00:38:31 dhcp snoopy[1075]: [starter:user, uid:root euid:root gid:root egid:root sid:1069 tty:/dev/pts/1 cwd:/home/user filename:/bin/ls]: ls
Log owner of current tty
set tty_uid to -1 by default, so that tty_uid:0 is always meaningful
Added ability to log environment variables
Add x86_64 support to detect.c
Update spec to use github, rpm macros, and include detect
Add x86_64 support to detect.c
Removed external filtering feature, too dangerous

Reason: Systems were thrown into infinite loops if only single
improper command was executed by the filter (improper means that
command path was not in the exclusion list).

The decision was:
- remove external filtering
- implement internal filtering
- internal filtering must be configurable
Removed configure file, added autogen.sh to generate configure file on the fly, fixed documentation
Removed stale filtering contents (readme and header defines)
Initial gitignore file created
Major refactoring:
- version 2.0.0rc1
- preparing for new features, with configuration etc
- separated inputs into separate files (snoopy_input*)
- reparated logging facilities into separate file (snoopy_log.*)
- storing filename and argv/envp (TODO) in global variables, so they can be consumed by inputs if requred
- only execv()/execve() wrappers still in snoopy.c
- added snoopy-test-output program
- fixed makefile to support -jX
Re-added accidentally lost functionality for root-only logging
Refactoring: moved all code into src/ directory
Major refactoring: switched to autotools makefile.am build process, renamed library from snoopy.so to libsnoopy.so
Fixed enable make target: added install as dependency, fixed script that now removes stale /snoopy.so entry from ld.so.preload
Refactored input* files to inputregistry and inputdatastorage, to represent better what they mean
Updated autotools autogen.sh to use autoreconf rather than a chain of commands
Added dev helper binary to noinst makefile option, with loop through all inputs
Refactoring, renaming shared variables to snoopy_ prefix, removed inputCount variable