fix string.replace unit tests suites 15_5_4_10 15_5_4_11

fix string.replace unit tests suites 15_5_4_10 15_5_4_11
Fix string.split method and unit tests

Fix string.split method and unit tests
fixed method string.split() and unit tests part 2

fixed method string.split() and unit tests part 2
Skip unit tests because of double precision issue

Skip unit tests because of double precision issue
Fixed string.split()
fixed string.substring()
Fixed string.trim()
Sebastien's remarks
Sebastien remarks 2
Remove property Length
Replace  LINQ exp with foreach()
Merge pull request #3 from fredericaltorres/master

Fixing some string unit tests