Address code style and quality issues (#203)

Cleaned up by clang-tidy 7.0.0.
Enabled checks:
  - boost-use-to-string
  - misc-uniqueptr-reset-release
  - modernize-deprecated-headers
  - modernize-make-shared
  - modernize-use-bool-literals
  - modernize-use-equals-delete
  - modernize-use-nullptr
  - modernize-use-override
  - performance-unnecessary-copy-initialization
  - readability-container-size-empty
  - readability-redundant-string-cstr
  - readability-static-definition-in-anonymous-namespace
  - readability-uniqueptr-delete-release

See http://releases.llvm.org/7.0.0/tools/clang/tools/extra/docs/clang-tidy/index.html for details.

RecoLocalTracker/SiPixelRecHits/interface/PixelCPEFast.h

@@ -41,7 +41,7 @@ class PixelCPEFast final : public PixelCPEBase
                    const SiPixelGenErrorDBObject *, const SiPixelLorentzAngle *);
 
 
-   ~PixelCPEFast();
+   ~PixelCPEFast() override;
 
     // The return value can only be used safely in kernels launched on
     // the same cudaStream, or after cudaStreamSynchronize.