Simple patch to build shared library using autotools.
Additionally removes inappropriate declaration of 'CFLAGS'.

diff -dupr leptonlib-1.62.orig/src/Makefile.am leptonlib-1.62/src/Makefile.am
--- leptonlib-1.62.orig/src/Makefile.am	2009-12-16 18:49:59.800517773 +0100
+++ leptonlib-1.62/src/Makefile.am	2009-12-16 18:50:19.629265044 +0100
@@ -6,10 +6,10 @@ SUBDIRS =
 MAKE = make -f Makefile
 AM_CFLAGS = -D_BSD_SOURCE -DANSI -fPIC
 AM_CPPFLAGS = $(ENDIANNESS)
-CFLAGS = -O2
+AM_LDFLAGS = -shared
 
-lib_LIBRARIES = liblept.a
-liblept_a_SOURCES = adaptmap.c \
+lib_LTLIBRARIES = liblept.la
+liblept_la_SOURCES = adaptmap.c \
  affine.c affinecompose.c \
  arithlow.c arrayaccess.c \
  bardecode.c \
diff -dupr leptonlib-1.62.orig/configure.ac leptonlib-1.62/configure.ac
--- leptonlib-1.62.orig/configure.ac	2009-12-16 18:54:31.012265321 +0100
+++ leptonlib-1.62/configure.ac	2009-12-16 18:55:06.954265636 +0100
@@ -114,7 +114,7 @@ AC_C_BIGENDIAN
 
 # Check where all the following programs are and set
 # variables accordingly:
-AC_PROG_RANLIB
+AC_PROG_LIBTOOL
 # AC_PROG_LN_S
 # AC_PATH_PROG(MV, mv)
 # AC_PATH_PROG(CP, cp)