version 0.5
- Added Arithmetic (+, -, *, /, ^, %%, %/%) operators for ff vectors
- Added Compare & Logic (==, !=, <, <=, >=, >, &, |, !) operators for ff vectors 
- Added Math (abs, sign, sqrt, ceiling, floor, trunc, log, log10, log2, log1p, acos, acosh, asin, asinh, atan, atanh, exp, expm1, cos, cosh, sin, sinh, tan, tanh, gamma, lgamma, digamma, trigamma, round, signif) functions for ff vectors
- Added ffmatch & ffdfmatch function and overloaded the %in% operator
- Added ffwhich function
- Added laf_to_ffdf
- Added duplicated and unique for ff and ffdf
- Added is.na for ff vectors
- Changed merge.ffdf to work based on ffmatch in order to handle left outer joins correctly
- Fixed a bug in ffwhich.ff_vector
- ffappend and ffdfappend have an extra argument adjustvmode - defaulting to TRUE - which makes sure x is now coerced to a higher vmode if needed. This also affects the c.ff_vector operator.
- improved compact.ff
- Added save.ffdf, move.ffdf, load.ffdf, pack.ffdf and unpack.ffdf

version 0.4-1
- exported sum.ff, because RecordLinkage fails...

version 0.4
- Added many new functions ffdfdply, ffwhich, hist.ff, quantile.ff, cumsum, cummax
- Fixed bugs in 'with.ff' in combination with character and factor vectors.
- Welcomed a new contributer/author Jan Wijffels

version 0.3
- Added ffdfsave function that can be used to save an ffdf data.frame

version 0.2-2
- bug fix, subset for ffdf now works properly (thanks to Martijn Tennekes)

version 0.2-1
- bug fix, sum.ff with na.rm=TRUE is now working correctly (thanks to Andreas Borg)

version 0.2
- initial version
