Accept both CR and CRLF line ending file sizes.
Added a new test macro `FSL_CHECK_ERROR`
Improved FSL_CHECK so it doesn't need to declare a local variable.
Added a mechanism for joining paths (`fostlib::join_paths`) in the same sort of way that URL paths are joined.
Updated path joining so it'll work on Windows.
Should fix a Boost 1.40.0 problem.
Add a coercion so we can easily support older Boost versions.
Merge from develop
 ChangeLog                        |  9 ---------
 Cpp/fost-core/file-tests.cpp     | 20 +-------------------
 Cpp/fost-core/file.cpp           | 14 +-------------
 Cpp/fost-core/progress-tests.cpp |  8 ++------
 Cpp/include/fost/file.hpp        |  8 +-------
 Cpp/include/fost/test.hpp        | 38 ++++----------------------------------
 6 files changed, 9 insertions(+), 88 deletions(-)