Added support to window CI (appveyor)

[brunogouveia]

Issue #4 , if available:

Description of changes:

• Added an option to link benchmark/parser lib/tests agains the static library (necessary by windows).
• Fixed the HT_API definition to be resolved to nothing when building against static lib.
• Added appveyor config file that will build, run tests and benchmark.

Ex: https://ci.appveyor.com/project/brunohgouveia/hawktracer/build/1.0.19

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.