Changelog ideas-1.4 => ideas.1.5

* upgrade to ghc-7.10
* reintroducing dependency on standard cgi library
* adding missing instances for Term and ShowString
* new option for JSON mode: exercise terms can be encoded in JSON
* switched to QuickCheck's random number generator QCGen
* requests can fix the random seed
* added Term to service types, encoders and decoders
* JSON-Int can be used for decoded environments
* new implementation for interleave and atomic prefix combinators (more lazy)
* bug fix: "no prefix" now handled by json decoder


Changelog ideas-1.3.1 => ideas.1.4
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* refactoring of strategies
  - strategies are now represented cyclic trees (that preserve fixpoints)
  - new strategy combinators can be defined outside the framework
  - simpler interfaces: no more Builder, Step, and Core datatypes
  - nice speed-up for constructing and running strategies
  
* support for new database schema (v2) with more columns
  - request can have an optional 'logging' attribute (false, v1, v2)
  - command-line flag for seeing information that is logged 
  - userid, sessionid, and taskid are stored in a state

* changing license to Apache License version 2.0 (was: GPL)
* renaming strategy combinators (eg .*.) to solve clash with Applicative.<*> 
* adding SyntaxError constructor to Diagnose datatype
* added read instance for Difficulty
* changed newline and tab escaping in JSON
* re-implemented atomic combinator
* introduced inits combinator  (initial prefixes) and atomic prefix (!~>)
* introduced somewhereWhen traversal combinator
* added cabal flag to resolve dependency on network >= 2.6
* added cabal flag to enable support for logging