Added xpath expressions.
Added tests for new hocr xpath expressions.
Fixed comment in algorithms.py.
Added the spellcheck_hocr function in hocr.py with tests.
Added the in_file_dictionary function with test.
Added the function mapped_sym_suggest_with_filedict to algorithms.py.
Added tests for said function.
Added the function spellcheck_hocr_with_filedict with tests.