Revert "filenames fixed: extension to lower case"

This reverts commit ae465cc.

That commit to revert was wrong: an upper-case file extension enables
preprocessing (see https://gcc.gnu.org/onlinedocs/gfortran/Preprocessing-Options.html)
which is required to parse #if defined(_OPENMP) directives correctly.

Author: jip

SRC/chetrd_hb2st.f renamed to SRC/chetrd_hb2st.F

@@ -7,11 +7,11 @@
 *
 *> \htmlonly
 *> Download IPARAM2STAGE + dependencies 
-*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/iparam2stage.f"> 
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/iparam2stage.F"> 
 *> [TGZ]</a> 
-*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/iparam2stage.f"> 
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/iparam2stage.F"> 
 *> [ZIP]</a>
-*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/iparam2stage.f"> 
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/iparam2stage.F"> 
 *> [TXT]</a>
 *> \endhtmlonly 
 *