Class.3

Re-generated man pages and tutorials

improve spelling

* configure.ac, configure: Fix package version to include patch level (was dropped unintentionally); regenerated docs

Update copyright years [skip ci]

* nx.tcl, properties.test: Add exists accessor to properties and variables; incl. tests and documentation

* nsf.c (NsfOUplevelMethod, NsfOUpvarMethod, NsfCallstackFindCallingContext): Reform of uplevel and upvar methods, based on the recent feedback by Zoran. First, uplevel and upvar methods, as well as [current callinglevel] now behave consistently (re frame skipping for mixin and filter transparency). If there is no innermost enclosing proc frame, the innermost non-proc (e.g., namespace) frame is selected (rather than a "#0" as default). Second, argument handling for both uplevel (i.e., level sniffing in multi-arg case) and upvar (e.g., made silent TCL_ERROR for invalid argument arities explicit) have been fixed. * Object.man, methods.test: Added documentation for both methods (Object.man) and tests.

Regenerated NROFF for nx::Class

* nx.tcl (VariableSlot): Fix value=delete to actually accept and implement "-nocomplain". Added tests (missing so far entirely) and updated the man pages accordingly.

* property.man.inc, variable.man.inc: Add missing doc on -trace option.

Docs: Link version numbering in man pages to autoconf tooling (similar to the NaviServer setup), update copyright dates in man pages where needed

Adding doc fragments for new info submethods, as well as deprecated and debug flags

- adding .3 man pages to ease installation