I have javascript files that I need them to be saved in UTF-8 (without BOM), every time I convert them to the correct format in Notepad++, they are reverted back to
Recently I found this tiny command-line tool which adds or removes the BOM on arbitary UTF-8 encoded files: UTF BOM Utils (new link at github)
Little drawback, you can download only the plain C++ source code. You have to create the makefile (with CMake, for example) and compile it by yourself, binaries are not provided on this page. However, for a software developer this should not be any issue.