Set minimum threshold (10) for file search

Closes #142

#### Default 10
![default-min](https://cloud.githubusercontent.com/assets/96776/4943948/4a19b3bc-65f9-11e4-9b51-493a4edbfa59.png)

#### Reduced minimum
![reduced-min](https://cloud.githubusercontent.com/assets/96776/4943950/4a1ed96e-65f9-11e4-9223-e7ccda100cdb.png)

#### Embed form option
![embed-this](https://cloud.githubusercontent.com/assets/96776/4943949/4a1d94fa-65f9-11e4-96a5-463638d78cf3.png)