Modify search(), Organize Testing.java

search():
Relation between keywords in keywordStr change from OR to AND, adding
keywords lead to a more accurate search result
Testing.java:
The code to test written into different function start with "search",
"sketch" or "compare" to preform better and reusable testings
Merge pull request #12 from DustInMonteriggioni/Branch-chyb

Modify search(), Organize Testing.java