Fixing Compiler Error C2466
Remove unused function StackString() and class CCoins;
Discover some missing includes
Merge pull request #4810

c0f5d4a Fixing Compiler Error C2466 (ENikS)
Merge pull request #4812

53efb09 Discover some missing includes (jtimon)
8d5e510 Remove unused function StackString() and class CCoins; (jtimon)
Create build-aux/m4 dir. Move m4 scripts for out-of-src builds.
Remove pkg.m4. Update .gitignore.