maint: Use phrase "FIXME:" for problem areas in code. * libinterp/corefcn/betainc.cc, libinterp/corefcn/bitfcns.cc, libinterp/corefcn/display.cc, libinterp/corefcn/gammainc.cc, libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/graphics.cc, libinterp/corefcn/load-save.cc, libinterp/corefcn/ls-hdf5.cc, libinterp/corefcn/ls-mat5.cc, libinterp/corefcn/ls-oct-binary.cc, libinterp/corefcn/luinc.cc, libinterp/corefcn/mex.cc, libinterp/corefcn/regexp.cc, libinterp/corefcn/sighandlers.cc, libinterp/corefcn/sparse-xpow.cc, libinterp/corefcn/urlwrite.cc, libinterp/corefcn/variables.cc, libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/__magick_read__.cc, libinterp/dldfcn/chol.cc, libinterp/octave-value/ov-bool-sparse.cc, libinterp/octave-value/ov-fcn-inline.cc, libinterp/octave-value/ov-flt-re-mat.cc, libinterp/octave-value/ov-re-mat.cc, libinterp/octave-value/ov-str-mat.cc, libinterp/parse-tree/lex.ll, liboctave/numeric/SparseCmplxQR.cc, liboctave/numeric/SparseQR.cc, liboctave/numeric/sparse-dmsolve.cc, liboctave/util/lo-utils.cc, liboctave/util/sparse-util.cc, liboctave/util/url-transfer.cc: maint: Use phrase "FIXME:" for problem areas in code.

--- a/liboctave/numeric/SparseQR.cc
+++ b/liboctave/numeric/SparseQR.cc
@@ -79,7 +79,7 @@
 {
 #ifdef HAVE_CXSPARSE
   // Drop zeros from V and sort
-  // FIXME Is the double transpose to sort necessary?
+  // FIXME: Is the double transpose to sort necessary?
   BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
   CXSPARSE_DNAME (_dropzeros) (N->L);
   CXSPARSE_DNAME () *D = CXSPARSE_DNAME (_transpose) (N->L, 1);
@@ -143,7 +143,7 @@
 {
 #ifdef HAVE_CXSPARSE
   // Drop zeros from R and sort
-  // FIXME Is the double transpose to sort necessary?
+  // FIXME: Is the double transpose to sort necessary?
   BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
   CXSPARSE_DNAME (_dropzeros) (N->U);
   CXSPARSE_DNAME () *D = CXSPARSE_DNAME (_transpose) (N->U, 1);