apr: bump to 1.7.0 & sync with master

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

40a29bf055
40c7e95210
893a804c95
12037b3f29
193c3913b6
430ab5f9b3
0c6d461cc9
86396c6a49

Short summary:

- version is bumped to 1.7.0
- Makefile and patches are updated and cleaned
- adds myself as maintainer
- improves the cross-compile setup (via configure variables, patches &
  sed scripts)

For more details please check the individual commits provided above.

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

libs/apr/patches/002-sys-param-h.patch

@@ -0,0 +1,37 @@
+Fix PATH_MAX detection by including sys/param.h if available
+
+Patch sent upstream:
+https://bz.apache.org/bugzilla/show_bug.cgi?id=63782
+
+Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
+
+--- a/configure.in
++++ b/configure.in
+@@ -1596,6 +1596,7 @@ AC_SUBST(stdlibh)
+ AC_SUBST(stringh)
+ AC_SUBST(stringsh)
+ AC_SUBST(sys_ioctlh)
++AC_SUBST(sys_paramh)
+ AC_SUBST(sys_sendfileh)
+ AC_SUBST(sys_signalh)
+ AC_SUBST(sys_socketh)
+--- a/include/apr.h.in
++++ b/include/apr.h.in
+@@ -95,6 +95,7 @@
+ #define APR_HAVE_STRINGS_H       @stringsh@
+ #define APR_HAVE_INTTYPES_H      @inttypesh@
+ #define APR_HAVE_SYS_IOCTL_H     @sys_ioctlh@
++#define APR_HAVE_SYS_PARAM_H     @sys_paramh@
+ #define APR_HAVE_SYS_SENDFILE_H  @sys_sendfileh@
+ #define APR_HAVE_SYS_SIGNAL_H    @sys_signalh@
+ #define APR_HAVE_SYS_SOCKET_H    @sys_socketh@
+@@ -218,6 +219,9 @@
+ #ifdef __cplusplus
+ extern "C" {
+ #endif
++#if APR_HAVE_SYS_PARAM_H
++#include <sys/param.h>
++#endif
+ 
+ /**
+  * @addtogroup apr_platform