Firebird doesn't support MSVC 2015

[Stephan Bergmann]

On 03/02/2016 07:25 PM, Alexander Thurgood wrote:
> Toolchain problems on OSX with firebird too...currently not building
> with firebird enabled in my own master builds, as the build fails each
> time when I do.

* "When building LibreOffice on OS X 10.11 you currently need to use at 
least --disable-firebird-sdbc." 
(<https://wiki.documentfoundation.org/Development/BuildingOnMac>)

* See 
<https://lists.freedesktop.org/archives/libreoffice/2016-February/073399.html> 
"Compilation on OS X 10.11" for why you might need to explicitly 
configure --disable-firebird-sdbc, and why it might be set implicitly 
instead, depending on your master revision.

* See the commit message of 
<https://cgit.freedesktop.org/libreoffice/core/commit/?id=ce170cf1f264c69e91cde268ee490584c8fbcd04> 
"Allow external/firebird to be built with a custom SHELL under Mac OS X 
10.11" for how to build external/firebird on 10.11 after all ("build 
your own bash and pass it to make with SHELL=...").