cleanup: Remove ports depending on expired lang/gcc6-aux

Keep ports-mgmt/synth and dependencies (including lang/gcc6-aux itself)
for now as synth is the only Ada port still maintained and might be
somewhat high-profile.

Removed ports:
archivers/zip-ada
cad/ghdl
databases/adabase
databases/apq
databases/apq-mysql
databases/apq-odbc
databases/apq-pgsql
devel/ada-util

Remove # $FreeBSD$ from Makefiles.

Bump PORTREVISIONs of all users of math/mpc that we just updated to
version 1.1.0 (via revision 464079).

- Switch to options helpers

Approved by:	portmgr blanket

Return ports maintained by John Marino to the pool, he is no longer interested.

Submitted by:	Mark Millard via private e-mail

Return the ports mistakenly reset to ports@ in r433856 to John Marino.

The mistake was completely on my part, I somehow connected the dots the
wrong way in my head.

The only exceptions (for now) are archivers/zstd and ports-mgmt/synth
which were already picked up by new volunteers in the mean time.

Return ports maintained by John Marino to the pool, see r433827 for details

Change Ada Framework foundation from gcc5-aux to gcc6-aux

GCC 6.1 was released this week.  The Ada Framework in FreeBSD ports has
been based on GCC 5.3 GNAT although GCC 6.x has been supported for awhile
via the ADA_DEFAULT option in make.conf.

Now that GCC 6 has been officially released, switch to it by default.
People can maintain the old foundation by putting "ADA_DEFAULT=5" in
/etc/make.conf.

Libraries built by one GNAT are unusable by another, so almost every Ada
port has been bumped as a result.  Noticable exceptions are dns/ironsides
which fails to build on gcc6 (thus USES=ada:5 is set) and cad/ghdl which
needs additional testing as it may require gcc5 on FreeBSD (DragonFly
uses the LLVM backend only).

misc/excel-writer: upgrade version 14 => 15

Remove @dirrm from package list of 8 of my ports

misc/excel-writer: Upgrade version 13 => 14

misc/excel-writer: Update version 12 => 13

From recent http://planet.ada.cx feed: Excel Writer v.13

Some recently added features:
  * freeze panes
  * cell comments
  * vertical text alignment
  * text orientation
  * Ada.Calendar.Time Put/Write and date built-in formats
  * background colours
  * wrap_text format option
  * Next and Next_Row
  * Text_IO's New_Line(lines), Line, Col now available

Excel Writer (Excel_Out) is a free, standalone, portable, open source
package for producing Excel spreadsheets with basic formattings and
page layout. It can be used in an "Ada.Text_IO" fashion, with Put,
Put_Line and New_Line.

misc/excel-writer: Upgrade version 11 -> 12

misc/excel-writer: Update version 07 to 11

Due to a change in how files were being stored at SourceForge, I didn't
realize that version 11 is actually the latest.

misc/excel-writer: Ensure short description includes "Ada"

This is important as the package is not (easily) usable for those
uninterested in Ada.

Add new Ada port: misc/excel_writer

Excel_Out is a package that can generate basically formatted Excel files.

* Ideal for the automatic production of reports
* Fast: on a HP Mini netbook (Intel Atom, 1.66 GHz), Excel Writer produced
  50 sheets per second where each sheet had 10,000 data cells
* Totally portable and no external library required
* No interation with MS Office software

WWW: http://excel-writer.sourceforge.net