Create a __no_return__ macro to flag a function as not returning.

This is needed to compile with clang >= 3.1, as clang demands
functions that don't return to be marked as such. This is the case
for any function that always throws for instance, which we currently
have two off.
Added .travis.yml
Fixed failure on AllocLetTestFree.Create

Fixed cmake macro
Removed extra semicolon (cause compiler error on clang 3.2 -Werror -Wall)
Disabled clang's Wmissing-variable-declarations.

Wmissing-variable-declarations forces 'extern' declaration for all
global variable definitions.
It it hard to shut up all of warnings because UtestMacros.h has
many global variable definitions in its macros.
Avoid MemoryLeakOperatorOverloadsTest failure on clang-3.2

if CMAKE_BUILD_TYPE is RelWithDebInfo or Release,
MemoryLeakOperatorOverloadsTest fails.

cpputest/tests/MemoryLeakOperatorOverloadsTest.cpp:344: error: Failure in TEST(OutOfMemoryTestsForOperatorNew, FailingNewArrayOperatorThrowsAnExceptionWhenUsingStdCppNewWithoutOverride)
	Should have thrown an exception!
.
cpputest/tests/MemoryLeakOperatorOverloadsTest.cpp:334: error: Failure in TEST(OutOfMemoryTestsForOperatorNew, FailingNewOperatorThrowsAnExceptionWhenUsingStdCppNewWithoutOverride)
	Should have thrown an exception!
Merge remote-tracking branch 'origin/master'

Conflicts:
	.travis.yml
Avoid linker error when using autotools with clang on travis.

Instead of autotools, CMake can be used to test gmock and gtest integration.
Fixed mistake using CXX instead of C.