Improved flood control counting to strictly not allow more than
the given amount of messages in the configured interval.

The previous behavior allowed n+2 messages in the interval, due to
two off by one comparison rules.

In addition, if flooding is detected then each new message after the flooding
is detected will reset the interval timer, which means the client
cannot send another message until the timeout interval expires.
Fix CMake/SQLite path issues on 64-bit Ubuntu 14.04
Fix cmake script for searching sqlite3 properly.

This is important for Debian, Ubuntu and other systems based on them. Details:
  https://wiki.debian.org/Multiarch
  https://wiki.ubuntu.com/MultiarchSpec

Have in mind that there are MIPS, ARM and many other architectures...
Delete extra option from cmake rules.

Conflicts:
	CMakeLists.txt
Fix build with clang.
Add support of Travis CI.
Fix compile warning due to missing newline at EOF.
Fix crashing autotest due to wrong initialization of the usermanager.

Conflicts:
	autotest/test_inf.tcc
Remove usage of strcat, since OpenBSD does not like that.
Fix copyright year.

Conflicts:
	src/core/gen_config.c
	src/core/gen_config.h
	src/plugins/mod_chat_history_sqlite.c
	src/plugins/mod_chat_is_privileged.c
	src/plugins/mod_chat_only.c
	src/plugins/mod_no_guest_downloads.c
Fix Clang compile warnings.