Refined definition of numeric types and traits.

Introduced OFlonglong and OFulonglong preprocessor definitions that
expand to the platform specific long long type or are undefined if
no such type is available.
Reimplemented fixed width integer types employing these long long
types and refined integer traits to use the primitive types instead
of the fixed with types in their specializations.
Fixed a problem with Microsoft Safe CRT in oflog.

The oflog module now honors the configure test results instead of using
its own definitions.
New compare() function for dcmdata object values.

A new compare() function is added to all VR classes under the DcmElement
object hierarchy which compares two objects (of the same type) by
value. The function takes into account that elements may have different
tags, values and VMs.
Make sure dcmdata tests compile with autoconf.