src/riemann-client: Code cleanup

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
src/riemann-client: Split into smaller files

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
src/riemann-client: Refactor the main() function

Use a function map to call the functions, instead of if/else pairs.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
message: Code cleanup

Removed an unreachable branch from riemann_message_set_events().

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
message: Removed an unneeded empty line

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>