Updated build docs w.r.t. Android and binary sizes

# Google Android makefile for curl and libcurl

#

# Please read also the Android section in docs/INSTALL for alternate methods!

# This file can be used when building curl using the full Android source

# release or the NDK. Most users do not want or need to do this; please

# instead read the Android section in docs/INSTALL for alternate

# methods.

#

# Place the curl source (including this makefile) into external/curl/ in the

# Android source tree.  Then build them with 'make curl' or just 'make libcurl'

   The GNU compiler and linker have a number of options that can reduce the

   size of the libcurl dynamic libraries on some platforms even further.

   Specify them by providing appropriate CFLAGS and LDFLAGS variables on the

   configure command-line:

     CFLAGS="-ffunction-sections -fdata-sections" \

   configure command-line, e.g.

     CFLAGS="-Os -ffunction-sections -fdata-sections \

             -fno-unwind-tables -fno-asynchronous-unwind-tables" \

     LDFLAGS="-Wl,-s -Wl,-Bsymbolic -Wl,--gc-sections"

   Be sure also to strip debugging symbols from your binaries after

   .comment section).

   Using these techniques it is possible to create a basic HTTP-only shared

   libcurl library for i386 Linux platforms that is only 101 KiB in size, and

   an FTP-only library that is 105 KiB in size (as of libcurl version 7.21.5,

   using gcc 4.4.3).

   libcurl library for i386 Linux platforms that is only 106 KiB in size, and

   an FTP-only library that is 108 KiB in size (as of libcurl version 7.27.0,

   using gcc 4.6.3).

   You may find that statically linking libcurl to your application will

   result in a lower total size than dynamically linking.