top: extend rcfile conversions for '--enable-oomem'

top: extend rcfile conversions for '--enable-oomem'

Under openSUSE, old top uses additional fields for
out-of-memory reporting.  As a result, under the
original approach to rcfile conversion, new top would
issue a fatal corrupt window entry message asking that
the rcfile be deleted.

This patch extends the conversion range to include
the extra openSUSE field characters.  It's effective
when ./configure specifies the --enable-oomem option
which in turn defines OOMEM_ENABLE.

This commit also makes the conversion logic slightly
more forgiving.  While enforcing an upper limit on the
expected number of old style field characters, amounts
less than that will be handled seemlessly.

Reference:
commit 4b987331323fe7b0d8a8566c33b786682acf12c9

Signed-off-by: Jim Warner <james.warner@comcast.net>