Make the Solidity repository standalone.

This commit is the culmination of several months of work to decouple Solidity from the webthree-umbrella so that it can be developed in parallel with cpp-ethereum (the Ethereum C++ runtime) and so that even for the Solidity unit-tests there is no hard-dependency onto the C++ runtime.

The Tests-over-IPC refactoring was a major step in the same process which was already committed.

This commit contains the following changes:

- A subset of the CMake functionality in webthree-helpers was extracted and tailored for Solidity into ./cmake.   Further cleanup is certainly possible.
- A subset of the libdevcore functionality in libweb3core was extracted and tailored for Solidity into ./libdevcore.   Further cleanup is certainly possible
- The gas price constants in EVMSchedule were orphaned into libevmasm.
- Some other refactorings and cleanups were made to sever unnecessary EVM dependencies in the Solidity unit-tests.
- TravisCI and Appveyor support was added, covering builds and running of the unit-tests (Linux and macOS only for now)
- A bug-fix was made to get the Tests-over-IPC running on macOS.
- There are still reliability issues in the unit-tests, which need immediate attention.    The Travis build has been flipped to run the unit-tests 5 times, to try to flush these out.
- The Emscripten automation which was previously in webthree-umbrella was merged into the TravisCI automation here.
- The development ZIP deployment step has been commented out, but we will want to read that ONLY for release branch.

Further iteration on these changes will definitely be needed, but I feel these have got to sufficient maturity than holding them back further isn't winning us anything.    It is go time :-)

cmake/EthOptions.cmake

@@ -0,0 +1,40 @@
+macro(configure_project)
+	set(NAME ${PROJECT_NAME})
+
+	# features
+	eth_default_option(PROFILING OFF)
+
+	# components
+	eth_default_option(TESTS ON)
+	eth_default_option(TOOLS ON)
+
+	# Define a matching property name of each of the "features".
+	foreach(FEATURE ${ARGN})
+		set(SUPPORT_${FEATURE} TRUE)
+	endforeach()
+
+	include(EthBuildInfo)
+	create_build_info(${NAME})
+	print_config(${NAME})
+endmacro()
+
+macro(print_config NAME)
+	message("")
+	message("------------------------------------------------------------------------")
+	message("-- Configuring ${NAME}")
+	message("------------------------------------------------------------------------")
+	message("--                  CMake Version                            ${CMAKE_VERSION}")
+	message("-- CMAKE_BUILD_TYPE Build type                               ${CMAKE_BUILD_TYPE}")
+	message("-- TARGET_PLATFORM  Target platform                          ${CMAKE_SYSTEM_NAME}")
+	message("--------------------------------------------------------------- features")
+	message("-- PROFILING        Profiling support                        ${PROFILING}")
+	message("------------------------------------------------------------- components")
+if (SUPPORT_TESTS)
+	message("-- TESTS            Build tests                              ${TESTS}")
+endif()
+if (SUPPORT_TOOLS)
+	message("-- TOOLS            Build tools                              ${TOOLS}")
+endif()
+	message("------------------------------------------------------------------------")
+	message("")
+endmacro()