* configure.ac (AC_CHECK_WITH_CLASSPATH_INCLUDEDIR): Removed.

* configure.ac (AC_CHECK_WITH_CLASSPATH_INCLUDEDIR): Removed.
[!WITH_JRE_LAYOUT] (AC_CHECK_WITH_CLASSPATH_LIBDIR): Conditional.
(AC_CHECK_WITH_JNI_MD_H): Added.
(AC_CHECK_WITH_JNI_H): Likewise.
(AM_CPPFLAGS): Added.

* m4/classpath.m4 (AC_CHECK_WITH_CLASSPATH_INCLUDEDIR): Removed.
(AC_CHECK_WITH_JNI_MD_H): New macro.
(AC_CHECK_WITH_JNI_H): Likewise.

* src/native/jni.h (__GCJ_JNI_MD_H__): Removed the quick hack.
(CLASSPATH_JNI_MD_H): Removed.
(CLASSPATH_JNI_H): Likewise.
(INCLUDE_JNI_MD_H): Added.
(INCLUDE_JNI_H): Likewise.