Revert "Open compare_word_by_text() for bsearch() in gen_IM_data."

This reverts commit 1afde14090c39f7e6cfd6c40efb79e9b0c6540b2, considering that comrare_word_by_text() compares phones of the same text, but I'm under the situation of searching its pronunciation.
Let gen_IM_data enumerate all probilities of keyin sequences.
Fix comment error.