zlib is not needed since the move to librevenge

Change-Id: Ib83663e9cc7a808db966cd8dfb3fbcd1ee195da6

Author: dtardon

README

@@ -1,7 +1,7 @@
 libvisio is a library and a set of tools for reading and converting MS
 Visio diagrams.
 
-libvisio requires boost, gperf, icu, librevenge, libxml2, perl and zlib
+libvisio requires boost, gperf, icu, librevenge, libxml2 and perl
 to build. Most up to date code is available from Git repository at
 libreoffice.org (https://gerrit.libreoffice.org/gitweb?p=libvisio.git)
 or the mirror at freedesktop.org

configure.ac

@@ -76,18 +76,6 @@ PKG_CHECK_MODULES([ICU],[icu-i18n],[
 AC_SUBST(ICU_CFLAGS)
 AC_SUBST(ICU_LIBS)
 
-# =========
-# Find zlib
-# =========
-PKG_CHECK_MODULES([ZLIB],[zlib],[],[
-    AC_CHECK_HEADER(zlib.h, [ZLIB_CFLAGS=],
-        [AC_MSG_ERROR(zlib.h not found. install zlib)], [])
-    AC_CHECK_LIB(z, inflate, [ ZLIB_LIBS=-lz ],
-        [AC_MSG_ERROR(zlib not found or functional)], [])
-])
-AC_SUBST(ZLIB_CFLAGS)
-AC_SUBST(ZLIB_LIBS)
-
 # ===========================
 # Find required boost headers
 # ===========================

libvisio.pc.in

@@ -10,4 +10,4 @@ Requires: librevenge-0.0
 Libs: -L${libdir} -lvisio-@VSD_MAJOR_VERSION@.@VSD_MINOR_VERSION@
 Cflags: -I${includedir}/libvisio-@VSD_MAJOR_VERSION@.@VSD_MINOR_VERSION@
 
-Requires.private: icu-i18n libxml-2.0 zlib
+Requires.private: icu-i18n libxml-2.0