Remove zlib

The library no longer uses zlib, so we can remove the option to build
with zlib.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ec95d9a..73e0a26 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,8 +5,6 @@
     project("mbed TLS" C)
 endif()
 
-option(ENABLE_ZLIB_SUPPORT "Build mbed TLS with zlib library." OFF)
-
 option(ENABLE_PROGRAMS "Build mbed TLS programs." ON)
 
 option(UNSAFE_BUILD "Allow unsafe builds. These builds ARE NOT SECURE." OFF)
@@ -169,14 +167,6 @@
 include_directories(include/)
 include_directories(library/)
 
-if(ENABLE_ZLIB_SUPPORT)
-    find_package(ZLIB)
-
-    if(ZLIB_FOUND)
-        include_directories(${ZLIB_INCLUDE_DIR})
-    endif(ZLIB_FOUND)
-endif(ENABLE_ZLIB_SUPPORT)
-
 add_subdirectory(library)
 add_subdirectory(include)
 
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 9e4a90a..6ac507f 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -123,10 +123,6 @@
     set(libs ${libs} network)
 endif(HAIKU)
 
-if(ENABLE_ZLIB_SUPPORT)
-    set(libs ${libs} ${ZLIB_LIBRARIES})
-endif(ENABLE_ZLIB_SUPPORT)
-
 if(LINK_WITH_PTHREAD)
     set(libs ${libs} pthread)
 endif()
diff --git a/programs/Makefile b/programs/Makefile
index 407a9a2..1b032de 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -41,11 +41,6 @@
 SHARED_SUFFIX=
 endif
 
-# Zlib shared library extensions:
-ifdef ZLIB
-LOCAL_LDFLAGS += -lz
-endif
-
 APPS = \
 	aes/aescrypt2$(EXEXT) \
 	aes/crypt_and_hash$(EXEXT) \
diff --git a/programs/test/CMakeLists.txt b/programs/test/CMakeLists.txt
index 0d2b946..59f8d54 100644
--- a/programs/test/CMakeLists.txt
+++ b/programs/test/CMakeLists.txt
@@ -2,10 +2,6 @@
     mbedtls
 )
 
-if(ENABLE_ZLIB_SUPPORT)
-    set(libs ${libs} ${ZLIB_LIBRARIES})
-endif(ENABLE_ZLIB_SUPPORT)
-
 add_executable(selftest selftest.c)
 target_link_libraries(selftest ${libs})
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1cfbd25..757ca5b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -2,10 +2,6 @@
     mbedtls
 )
 
-if(ENABLE_ZLIB_SUPPORT)
-    set(libs ${libs} ${ZLIB_LIBRARIES})
-endif(ENABLE_ZLIB_SUPPORT)
-
 find_package(Perl)
 if(NOT PERL_FOUND)
     message(FATAL_ERROR "Cannot build test suites without Perl")
diff --git a/tests/Makefile b/tests/Makefile
index 96c3d64..cb374e5 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -48,11 +48,6 @@
 PYTHON ?= python2
 endif
 
-# Zlib shared library extensions:
-ifdef ZLIB
-LOCAL_LDFLAGS += -lz
-endif
-
 # A test application is built for each suites/test_suite_*.data file.
 # Application name is same as .data file's base name and can be
 # constructed by stripping path 'suites/' and extension .data.