Use -dynamiclib instead of -shared for building shared libraries on OS X

Older toolchains don't recognize the -shared parameter.
Add the necessary directories to the include path within xcode

This is not necessary when using precompiled headers.
Remove unnecessary precompiled headers

This reduces the huge amount of near-useless small extra files
scattered around for the sake of the platform demo projects.

This requires explicitly listing all the ncessary include paths.
Merge pull request #348 from mstorsjo/darwin-dylib

Use -dynamiclib instead of -shared for building shared libraries on OS X
Add an SHA1 implementation by Paul Jones
Make the SHA1 header compatible with C++
Make the SHA1Result function write the output into a byte array
Use the bundled sha1 implementation instead of relying on openssl

This simplifies running tests on platforms where OpenSSL isn't
commonly available.
Use the local sha1 function names directly without compatibility defines
Remove the now unused -Wno-deprecated-declarations on OS X

This was only required for building with OpenSSL.
Set GTEST_HAS_TR1_TUPLE to 0 on msvc

This fixes building of gtest on msvc.

See e.g. http://stackoverflow.com/questions/8274588 for
more discussion on the matter.

This is only required on MSVC 2012 - gtest itself (in the cmake
files) adds -D_VARIADIC_MAX=10 to the build when building using
MSVC 2012, but we don't know the MSVC version at the make stage
here. Since the gtest tuple support isn't used at all, it's
simpler to just disable it altogether than to try to add
-D_VARIADIC_MAX=10.
Wrap the library names in codec_unittest LDFLAGS, for use with MSVC
Allow building tests on MSVC versions where stdint.h is missing

Of the supported MSVC versions, only 2008 actually is missing
stdint.h, it is included in MSVC since 2010.
Merge pull request #156 from mstorsjo/avoid-openssl

Get rid of the OpenSSL dependency by bundling a simple SHA1 implementation
Link codec_unittest to the static android STL

This allows building (and running) codec_unittest for android.

This explicitly needs to go at the end of the LDFLAGS, since both
this and -lgtest etc. are static libraries, and code in gtest
relies on the STL. Since this explicitly needs to be at the end,
a separate makefile variable is added for it.
Simplify the travis configuration now that OpenSSL isn't required any longer
Merge pull request #349 from mstorsjo/cleanup-ios-project

Remove unnecessary precompiled headers from the xcode projects
Merge pull request #350 from mstorsjo/android-unittest

Link codec_unittest to the static android STL
Merge pull request #351 from mstorsjo/simplify-travis

Simplify the travis configuration now that OpenSSL isn't required any longer
Don't install 32 bit zlib in travis builds

It shouldn't be necessary for anything in the build.