apr-util: sync with master

This is a squash of the following cherry-picked commits:

27c4723936
03124bf4b4
141bd55316
40c7e95210
1d25dcde24
ea5b746e58
a62c0e599b
a16b294805
c24f5d258b
f6c218e74d

Short summary:

- adds external modules (crypto-openssl dbd-mysql dbd-odbc dbd-pgsql
  dbd-sqlite3 dbm-gdbm ldap)
- Makefile and patches are updated and cleaned
- adds myself as maintainer
- improves the cross-compile setup (via configure variables sed scripts)

For more details please check the individual commits provided above.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

libs/apr-util/patches/004-avoid_ldap_by_defaut.patch

@@ -0,0 +1,34 @@
+From: Ryan Niebur <ryanryan52@gmail.com>
+Subject: by default --avoid-ldap since apache2 is the only user, and we don't
+ want to add extra dependencies to other apr-utils rdepends
+
+--- a/apu-config.in
++++ b/apu-config.in
+@@ -30,7 +30,8 @@ includedir="@includedir@"
+ LIBS="@APRUTIL_EXPORT_LIBS@"
+ INCLUDES="@APRUTIL_INCLUDES@"
+ LDFLAGS="@APRUTIL_LDFLAGS@"
+-LDAP_LIBS="@LDADD_ldap@"
++ORIG_LDAP_LIBS="@LDADD_ldap@"
++LDAP_LIBS=""
+ DBM_LIBS="@LDADD_dbm_db@ @LDADD_dbm_gdbm@ @LDADD_dbm_ndbm@"
+ 
+ APRUTIL_LIBNAME="@APRUTIL_LIBNAME@"
+@@ -55,7 +56,7 @@ Known values for OPTION are:
+   --includedir      print location where headers are installed
+   --ldflags         print linker flags
+   --libs            print library information
+-  --avoid-ldap      do not include ldap library information with --libs
++  --avoid-ldap      do not include ldap library information with --libs (default on OpenWrt)
+   --ldap-libs       print library information to link with ldap
+   --avoid-dbm       do not include DBM library information with --libs
+   --dbm-libs        print additional library information to link with DBM
+@@ -121,7 +122,7 @@ while test $# -gt 0; do
+     flags="$flags $LDAP_LIBS $DBM_LIBS $LIBS"
+     ;;
+     --ldap-libs)
+-    flags="$flags $LDAP_LIBS"
++    flags="$flags $ORIG_LDAP_LIBS"
+     ;;
+     --dbm-libs)
+     flags="$flags $DBM_LIBS"