removed SourcePosition, added SourceOffsetRange
Revert "removed SourceLocationConverter"

This reverts commit 764934e27474b3b1d5b695113e18ed8555729551.

Conflicts:
	library/CMakeLists.txt
	library/src/cppmanip/ClangFunctionExtractor.cpp
simplified SourceLocationConverterTest
switched back to using offsets instead of row/col
getFunctionStatements should_not_report_variables_not_visible_outside_of_statements
added StatementRange
getFunctionStatements should_temporarily_store_clang_statements
enabled -Wall and fixed warnings
swtiched from clang::StmtRange to ast::StatementRange
added sourceCode and sourceCode after to Statement
moved Statement and LocalVariable factory functions to AstFactories.hpp
removed unused helper methods and includes from tests
getFunctionStatements should_store_statments_source_code
getFunctionStatements should_store_source_code_between_statements
removed clang references from ast::Function and ast::Statement
removed unused clang includes
TranslationUnitFunctionExtractor takes a StatementExtractor instead of a factory
moved SourceLocationConverter to cppmanip::text