Register & enable filters + default ChunkReadFilter added
Register filter testcase
Implement import in chunks
Fixed a variable name in code documentation

Changed $firstRowAsIndex to $encoding in '_init' and 'load' functions
Merge pull request #204 from YAAK/1.2

Fixed a variable name in code documentation
Merge branch 'master' into 1.2
Merge branch '1.1' into 1.2
Merge master to 1.2
First setup of Request-like ExcelFile and NewExcelFile objects for constructor and method (l4.3) injection
Merge branch 'master' into 1.2
Fix tests
Import excel file handler functionality
Rename FileHandler to ImportHandler + add interfaces as contracts
Add ExportHandler functionality
ExcelFile, Import and ImportHandler tests
NewExcelFile, Export, ExportHandler tests
Add tests for filter enabling in ExcelFile import class
Merge branch '1.1' into 1.2
Make possible to append data to existing excel (and other modifications), fixes issue #208
Make possible to call export (and other writer methods) on an existing file, fixes issue #208