Fix couple of warnings seen in Android build.

On Android's libc (bionic) struct stat.st_mtime is defined as
unsigned long not time_t and this generates warnings.

The other fixes are related to casting of struct sockaddr in
listen() and bind() calls.

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@8338 4b0bc96b-bc66-0410-9d44-ebda105a78c1
Add support for building OSCam with Android NDK.

The fixes that are applied are:
 - For some reason Android NDK does not ship linux/serial.h
   Copy the needed headers in extapi/linux/
 - sys/shm.h does not exists but we are not using it anyway.
 - tcdrain() is not implemented in Bionic, provide replacement.
 - in_port_t is not defined in Bionic, define it.
 - getpwuid_r() is not implemented but using getpwuid() is fine
   because we are not calling this function from multiple threads.

After these fixes you can build OSCam using Android NDK following
these simple instructions:

1. Download the NDK from https://developer.android.com/tools/sdk/ndk/index.html
2. Unarchive the NDK.
3. Go to NDK directory and run:
   `build/tools/make-standalone-toolchain.sh --install-dir=/tmp/android`
4. Go to OSCam source directory and run:
   `make LIB_PTHREAD= CROSS=/tmp/android/bin/arm-linux-androideabi-`

Voila, you have built OSCam binary for Android.

The Android toolchain(s) does not have support out of the box for
openssl, libusb or PCSC. If you want to use them just install them
like you do in any other toolchain.

LIB_PTHREAD= must be used as `make` parameter because on Android
there is no need to link with pthread.

If you turn on IPV6SUPPORT there are some warnings which you can
just ignore.

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@8339 4b0bc96b-bc66-0410-9d44-ebda105a78c1