Added missing substr() method needed by gtest.

Collapsed 3 copy constructors into one with default values for the
pos and n values. string(const string&, size_t pos=0, size_t n=npos)

Extra test for substr and the copy constructor.
3 files changed
tree: e03f64ca35e6dbe4f3588f6678e7dc9c958b663f
  1. Android.mk
  2. README
  3. include/
  4. src/
  5. tests/