REORG: ebtree: clean up remains of the ebtree/ directory

The only leftovers were the unused compiler.h file and the LICENSE file
which is already mentioned in each and every ebtree file header.

A few build paths were updated in the contrib/ directory not to mention
this directory anymore, and all its occurrences were dropped from the
main makefile. From now on no other include path but include/ will be
needed anymore to build any file.
diff --git a/contrib/debug/Makefile b/contrib/debug/Makefile
index 385e0d1..74dd6ac 100644
--- a/contrib/debug/Makefile
+++ b/contrib/debug/Makefile
@@ -1,4 +1,4 @@
-INCLUDE  = -I../../include -I../../ebtree
+INCLUDE  = -I../../include
 
 CC       = gcc
 OPTIMIZE = -O2
diff --git a/contrib/halog/Makefile b/contrib/halog/Makefile
index 319942d..bf67c1f 100644
--- a/contrib/halog/Makefile
+++ b/contrib/halog/Makefile
@@ -1,5 +1,4 @@
-EBTREE_DIR = ../../ebtree
-INCLUDE  = -I../../include -I$(EBTREE_DIR)
+INCLUDE  = -I../../include
 SRC      = ../../src
 
 CC       = gcc
diff --git a/contrib/hpack/Makefile b/contrib/hpack/Makefile
index 4fce8db..1c6448b 100644
--- a/contrib/hpack/Makefile
+++ b/contrib/hpack/Makefile
@@ -1,4 +1,4 @@
-CFLAGS = -O2 -Wall -g -I../../include -I../../ebtree -fwrapv -fno-strict-aliasing
+CFLAGS = -O2 -Wall -g -I../../include -fwrapv -fno-strict-aliasing
 OBJS = gen-rht gen-enc decode
 
 all: $(OBJS)
diff --git a/contrib/hpack/decode.c b/contrib/hpack/decode.c
index 82f28c7..ce3b484 100644
--- a/contrib/hpack/decode.c
+++ b/contrib/hpack/decode.c
@@ -7,7 +7,7 @@
  * The DHT size may optionally be changed in argv[1].
  *
  * Build like this :
- *    gcc -I../../include -I../../ebtree -O0 -g -fno-strict-aliasing -fwrapv \
+ *    gcc -I../../include -O0 -g -fno-strict-aliasing -fwrapv \
  *        -o decode decode.c
  */
 
diff --git a/contrib/hpack/gen-enc.c b/contrib/hpack/gen-enc.c
index 44b643c..dfe4705 100644
--- a/contrib/hpack/gen-enc.c
+++ b/contrib/hpack/gen-enc.c
@@ -5,7 +5,7 @@
  * table is built to access the first entry of each length.
  *
  * Build like this :
- *    gcc -I../../include -I../../ebtree -o gen-enc gen-enc.c
+ *    gcc -I../../include -o gen-enc gen-enc.c
  */
 #define HPACK_STANDALONE
 
diff --git a/contrib/mod_defender/Makefile b/contrib/mod_defender/Makefile
index efc7d7f..ca06cef 100644
--- a/contrib/mod_defender/Makefile
+++ b/contrib/mod_defender/Makefile
@@ -28,7 +28,7 @@
 endif
 
 CFLAGS  += -g -Wall -pthread
-INCS += -I../../include -I../../ebtree -I$(MOD_DEFENDER_SRC) -I$(APACHE2_INC) -I$(APR_INC) -I$(EVENT_INC)
+INCS += -I../../include -I$(MOD_DEFENDER_SRC) -I$(APACHE2_INC) -I$(APR_INC) -I$(EVENT_INC)
 LIBS += -lpthread  $(EVENT_LIB) -levent_pthreads -lapr-1 -laprutil-1 -lstdc++ -lm
 
 CXXFLAGS = -g -std=gnu++11
diff --git a/contrib/modsecurity/Makefile b/contrib/modsecurity/Makefile
index aa0d6e3..93119b3 100644
--- a/contrib/modsecurity/Makefile
+++ b/contrib/modsecurity/Makefile
@@ -34,7 +34,7 @@
 endif
 
 CFLAGS  += -g -Wall -pthread
-INCS += -I../../include -I../../ebtree -I$(MODSEC_INC) -I$(APACHE2_INC) -I$(APR_INC) -I$(LIBXML_INC) -I$(EVENT_INC)
+INCS += -I../../include -I$(MODSEC_INC) -I$(APACHE2_INC) -I$(APR_INC) -I$(LIBXML_INC) -I$(EVENT_INC)
 LIBS += -lpthread  $(EVENT_LIB) -levent_pthreads -lcurl -lapr-1 -laprutil-1 -lxml2 -lpcre -lyajl
 
 OBJS = spoa.o modsec_wrapper.o
diff --git a/contrib/spoa_example/Makefile b/contrib/spoa_example/Makefile
index c44c2b8..a1c1eb5 100644
--- a/contrib/spoa_example/Makefile
+++ b/contrib/spoa_example/Makefile
@@ -6,7 +6,7 @@
 LD = $(CC)
 
 CFLAGS  = -g -O2 -Wall -Werror -pthread
-INCS += -I../../ebtree -I./include
+INCS += -I./include
 LIBS = -lpthread -levent -levent_pthreads
 
 OBJS = spoa.o