implement OSC /ardour/route/send/gainabs and /ardour/route/send/gainDB
correct previous premature commit re: OSC and send gain
fix context-menu entry sensitivity for plugins w/o custom GUI
fix typo in german translation
fix compiler warnings
fix about window close button
disable symbol export -- fix LinuxVST issue

-rdynamic:  Pass the flag -export-dynamic to the ELF linker,
 on targets that support it. This instructs the linker to add
 all symbols, not only used ones, to the dynamic symbol table.
 This option is needed for some uses of dlopen or to allow
obtaining backtraces from within a program.

Some LinuxVST pluging cause ardour3 to crash -- if ardour is linked with
-rdynamic (see #ardour log from 2013-jun-6). This is likely compiler
specific and not a problem on las' build-machine (gcc 4.5.5) which is
why the linux-packaging script enables it by default.
The issue can be reproduced reliably with gcc 4.7.2 and 4.6.3. Although
it is yet unclear if it is caused by g++/ld or related to other factors
of the build-system...
proper plugin-UI interaction/semantics

Always show plugin's own UI (if available) on double-click
Alt+double-click -> show 'generic controls'.
Context-menu offers both choices.
Use Tooltip for to make it discoverable.
fix crash when trying to show "controls" of processor w/o controls.
vtl: round fractional framerates to 1/100 to compare for identity
vtl: NOOP - clean up code.
possible fix for no-shutdown of external app (ie harvid)
close network sockets on fork

fixes problem with external apps (ie. video-server) inheriting them.
more sockets to close on fork()
mark more filedes as close-on-exec. - here audio+midi files!
some clarifying comments on WindowManager::set_transient_for
fix ssize_t/size_t confusion
Merge branch 'master' of git.ardour.org:ardour/ardour
OSC bail out if server cannot be started
more OSC socket fcntl() close-on-exec