Added configuration file support.

This patch adds the following functionality:
  * configuration file loading
  * default configuration printout
  * printing of loaded configuration
  * configuration testing
  * nicer --help message
  * version printing
  * addresses have new syntax: [HOST]:PORT
  * HOST,PORT arguments are still supported

Stud can still be built without configuration file support by
providing NO_CONFIG_FILE=1 argument to make

Author: Brane F. Gračnar

Diff for: .gitignore

@@ -1,2 +1,6 @@
-conf*
+conf
 ebtree*
+core
+core.*
+*.o
+stud

Diff for: Makefile

@@ -9,7 +9,7 @@ MANDIR  = $(PREFIX)/share/man
 
 CFLAGS  = -O2 -g -std=c99 -fno-strict-aliasing -Wall -W -D_GNU_SOURCE
 LDFLAGS = -lssl -lcrypto -lev
-OBJS    = stud.o ringbuffer.o
+OBJS    = stud.o ringbuffer.o configuration.o
 
 all: realall
 
@@ -28,6 +28,11 @@ ebtree:
 		exit 1 )
 endif
 
+# No config file support?
+ifneq ($(NO_CONFIG_FILE),)
+CFLAGS += -DNO_CONFIG_FILE
+endif
+
 ALL += stud
 realall: $(ALL)