API histogram Vector and Matcher

[nirizr]

This shouldn't be too difficult, and will require doing the following two tasks:

• Create a Vector of APIs called by a function (names of functions called by vectored function, that are in the .extern section or are empty, etc). This is somewhat similar to the MnemonicHistVector
• Create a Matcher that inherits the hash matcher and uses the new vector. This is similar to the MnemonicHist Matcher.