foonathan_memory_vendor FORCE_BUILD option

[xavisolesoft]

Proposal
I have a feature proposal for foonathan_memory_vendor package build:

My proposal consist on create a cmake option to be able to force the build even when ros is installed in the system path.
We need this option due we are using a different compiler from the system default one, so we need to force the build with our compiler.

Proposed implementation
I have an implementation proposal (I copy the snapshot because I have no permissions to create a branch in foonathan_memory_vendor):

How to use it
With the proposed implementation, force build can be enabled by passing the next argument to cmake in the command line:

-DFORCE_BUILD=ON

[JesusPoderoso]

Hi @xavisolesoft, thanks for using Fast DDS, and thanks for your proposal
Would you mind opening a Pull Request to follow up on it?
The procedure would be:

1. Fork the vendor repo
2. Implement the proposal on that fork
3. Open the PR from your fork to our repo

Thanks in advance!

[xavisolesoft]

Thanks.

I created this PR as suggested:
eProsima/foonathan_memory_vendor#69