Added config option to enable pprof

[xtda]

Description

Simple PR to enable pprof for ongoing performance testing

It adds a profiler config option that is disabled by default along with some Makefile aliases for ease of access with the net/http/pprof package for heap and CPU profiling

At the moment it listens on the same address as the REST interface this may change in future

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Automated testing using go test ./.. confirms all existing tests pass
Manual testing confirms pprof is working as intended when enabled

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation and regenerated documentation via the documentation tool
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally and on Travis with my changes
• Any dependent changes have been merged and published in downstream modules

[codecov-io]

Codecov Report

Merging #253 into master will decrease coverage by <.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #253      +/-   ##
==========================================
- Coverage   42.22%   42.21%   -0.01%     
==========================================
  Files         123      123              
  Lines       26619    26622       +3     
==========================================
  Hits        11239    11239              
- Misses      14453    14456       +3     
  Partials      927      927

Impacted Files	Coverage Δ
config/config.go	64.75% <ø> (ø)	⬆️
restful_router.go	0% <0%> (ø)	⬆️

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[thrasher-]

Note: If the webserver is disabled but the profiler config is enabled, then pprof won't load as it uses the same mux router as the webserver, as mentioned in the comment. This will be segregated in the engine branch.

[gloriousCode]

Good stuff 👍 Tested locally