Enable more and fix compiler warnings

[chfast]

No description provided.

[codecov-commenter]

Codecov Report

Merging #184 (d7ab6c1) into master (ec47e39) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #184   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           22        22           
  Lines         1652      1652           
=========================================
  Hits          1652      1652           

Flag	Coverage Δ
be	89.31% <ø> (ø)
default	99.81% <ø> (ø)
x86_64	89.06% <ø> (ø)

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Impacted Files	Coverage Δ
lib/global_context/global_context.cpp	100.00% <ø> (ø)
test/unittests/test_ethash.cpp	100.00% <ø> (ø)
test/unittests/test_keccak.cpp	100.00% <ø> (ø)
test/unittests/test_kiss.cpp	100.00% <ø> (ø)
test/unittests/test_progpow.cpp	100.00% <ø> (ø)