rem: bool install = false, bool makeExecutable = true)
add: bool install = false, bool makeExecutable = true, uint32 appFlags = B_SINGLE_LAUNCH)
context: create_app(const char *filename, const char *signature,		   bool install = false, bool makeExecutable = true){	BString testApp;	CHK(find_test_app("RosterLaunchTestApp1", &testApp) == B_OK);	system((string("cp ") + testApp.String() + " " + filename).c_str());	if (makeExecutable)		system((string("chmod a+x ") + filename).c_str());	BFile file;	CHK(file.SetTo(filename, B_READ_WRITE) == B_OK);	BAppFileInfo appFileInfo;	CHK(appFileInfo.SetTo(&file) == B_OK);	CHK(appFileInfo.SetSignature(signature) == B_OK);	CHK(appFileInfo.SetAppFlags(B_SINGLE_LAUNCH) == B_OK);	if (install)		CHK(BMimeType(signature).Install() == B_OK);	// We write the signature into a separate attribute, just in case we	// decide to also test files without BEOS:APP_SIG attribute.	BString signatureString(signature);	file.WriteAttrString("signature", &signatureString);}