gnetlist: fix nullor expansion in two spice backends

Some SPICE simulators (at least ngspice) don't allow using of
hyphen in element names (reference designators).  Now, the underscore
character is used instead of hyphen to form the vcvs element name
produced during nullor expansion.  (This is the same change as in commit
87eff64f2cd01cb90bbead6c9c19a6c5bf329a10 for controlled sources.)
gnetlist: use the same names for sources in spice and spice-sdb
gnetlist: reduced number of arguments of a procedure in the spice backend
gnetlist: move common functions of the spice backends into one file
gnetlist: removed unused and commented out code
gnetlist: fix two comments in the spice backend code
gnetlist: avoid invoking the same function twice
gnetlist: fix a comment in spice-sdb
gnetlist: fix nullor expansion

Nullor represents an ideal opamp, so its gain must be very high. If
the user forgets to add the value attribute to the nullor component,
the both spice backends will output non-working netlists. This cannot be
fixed just by fixing of the nullor-1.sym, since the user may have his/her
own nullor symbol, so the default gain value has been added here.
Fixed some attributes of the nullor symbol

Two missing attributes have been added: "value" and "symversion".
The "device" attribute has been moved to the visible area of gschem.
gnetlist: output two spice-sdb error messages to stderr
gnetlist: update Russian translation
gschem: localize one message
libgeda: update Russian translation
libgeda: fix localization of guile messages

This patch fixes guile output in localized environments where guile
outputs unicode sequences in form /uXXXX instead of localized strings.
This affects output to the terminal as well as to the gschem log window.

Probably, the issue has been introduced in guile 2.0. See discussion
at http://lists.gnu.org/archive/html/guile-user/2013-08/msg00066.html.

Affects-bug: lp-1083076
gsch2pcb: use proper paths to m4 files

Fixed the relative m4 data path in the pcb install directory.

Reported-by: Philipp Klostermann
gaf shell: output gEDA version to stderr instead of stdout

This prevents getting the version info into the data output by user
scripts, since the user may afterwards want, for example, to redirect
the data to a file.
Fix a couple of typos in comments
More precise comment for a function
libgeda: support of rotation and mirroring in '%set-complex!'

Make the '%set-complex!' procedure take into account angle and mirroring
of a new inserted from library component and modify its primitives
accordingly, so they are properly displayed in gschem after
'page-append!' and return correct coordinates while they are requested
by gaf shell.