Removed use of algorithm.txx header outside of core module
Removed use of algorithm.txx header outside of core module

- leads to attempted compilation of a non-exported symbol on windows
- fixed warnings caused with implicit size_t conversions in similarity
  transform estimation test cases.

linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk