Port Proced to Android

Port Proced to Android

* configure.ac (HAVE_PROCFS): Define if opsys is `android'.

* src/android.c (android_set_task_name): New function.
(android_run_select_thread, android_run_debug_thread): Set the
name of the LWP for debugging purposes.

* src/process.c (create_process): Set F_SETPIPE_SZ on Android in
addition to GNU/Linux.

* src/sysdep.c (procfs_ttyname, system_process_attributes)
[__ANDROID__]: Enable procfs_ttyname on Android systems.