gnucap-uf release

Hi there.

a first gnucap-uf release is ready for exploration and test drive [1].

gnucap-uf is a fork from gnucap that adds several features that cannot
really be put into plugins. gnucap-uf is coinstallable with gnucap and
meant to not interfere with it by virtue of the --program-suffix option
[2].

there are several modifications that don't make sense in upstream (yet),
some are worth consideration. for example

- standardized build system (here: autotools)
- automated test suite ('make check')
  (with tests intended to witness/document bugs)
- plugin compilation helper, knows where headers are etc.
  (used by automatic plugin compilation during 'attach').
- plugin versioning, reject plugins compiled for a different gnucap
- sensitivity analysis (draft)
- node voltage discontinuities and dynamic trsteporder
- changes in parameter scoping
- ELEMENT+BM accessibility from languages != spice
- steps towards making obsolete_callback obsolete

moreover, the release intends (currently is required) to make some
additional packages development possible, including

- gnucap-geda -- read from gschem schematics
- gnucap-adms -- verilog-a model compiler
- gnucap-bm -- noise, ir-filters, poly(k), etc.

many changes are (to) plugins. they work for us, but probably need
some polish before upstream integration. for example

- enhanced step control in dc analysis
- lang_{spectre,verilog,spice} (hacks and) improvements
- alternative bjt, improved (?) convergence
- sweep over parameters
- printf command
- dump and load voltages ("nodeset")

cheers
felix

[1] http://tool.em.cs.uni-frankfurt.de/~felix/gnucap-uf/gnucap-uf-0.0.0.tar.gz
[2] http://www.gnu.org/software/automake/manual/html_node/Renaming.html