Removing useless bytecode instructions 'RESERVE 0' and 'ADDTOP 0'
Adding several functions to interact with environment variables.

In addition to removing the superfluous 'isNullString' function,
now that I understand the FFI a bit better, there is a new
'getEnvPair' function that looks into the 'const char** environ'.
Setting, unsetting, and listing all of the environment variables is
now supported.
Refactoring of parser to Trifecta, documenting and updating some
items/fixing some issues.

Test 002 commented because of temporary disabling of TT quotation
support.

Regression Test 003 and Test 020 have updated expected values (which
fixes previously erranous line number report from old parser).
Merge pull request #490 from gabemc/issue/121

Removing useless bytecode instructions 'RESERVE 0' and 'ADDTOP 0'
Merge pull request #491 from gabemc/feature/environment

Adding several functions to interact with environment variables.
Merge branch 'master' of github.com:edwinb/Idris-dev
Fix building without LLVM
Fixed doc comments in multi-line comments bug
Fixed unspecified error on empty module without any declarations
Merge pull request #492 from ahmadsalim/master

New Parser in Trifecta
Merge pull request #493 from Melvar/master

Fix building without LLVM
Propagate function options to case blocks

In particuar, this means %assert_total gets propagated
Update version number to 0.9.9.2