Bug#930507: libompl-dev: libeigen required to build against OMPL

[Neil Dantam]

Package: libompl-dev
Version: 1.4.2+ds1-1
Severity: normal

Dear Maintainer,

   * What led up to the situation?

     Attempting to build against libompl on Buster.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

     I installed libompl-dev and used pkg-config to obtain compiler
     options to build against ompl.

   * What was the outcome of this action?

     The `Eigen/Core` header was not found.  This eigen header is
     referenced in `/usr/include/ompl/base/ProjectionEvaluator.h:49`.

   * What outcome did you expect instead?

     Eigen is automatically installed with libompl-dev and
     pkg-config sets the appropriate flags to find the Eigen headers.

     Specifically:

     1. Installing libompl-dev pulls libeigen3-dev as a dependency.

     2. The ompl.pc pkg-config file includes the appropriate flags
        to find the Eigen headers.  In OMPL 1.5.0, the generated ompl.pc
        includes `-I/usr/include/eigen3` in the cflags.


-- System Information:
Debian Release: 9.9
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-0.bpo.4-amd64 (SMP w/12 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8), LANGUAGE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libompl-dev depends on:
ii  libboost-dev  1.62.0.1
pn  libompl11     <none>
ii  pkg-config    0.29-4+b1

libompl-dev recommends no packages.

Versions of packages libompl-dev suggests:
ii  libode-dev  2:0.14-2