Added str_utils.h

strLen - computes string length
strCopy - copies a string
strCopyN - copies at most N characters of string
strConcatenate - appends src to the end of dst
strConcatenateN - appends at most N characters of str to dst
strCompare - compares two strings
strCompareN - compares at most N characters of two strings
strFind - searches first occurence of ch in str
strFind - searches first occurence of subStr in str
strFindAny - searches first occurence of any character among chList in
str
strFindAny - searches first occurence of any string among strList in str
Fixed "Output directory" warning

warning MSB8004: Output Directory does not end with a trailing slash.
This build instance will add the slash as it is required to allow proper
evaluation of the Output Directory.