copy ChangeLog from 2011.07

docs/ChangeLog

@@ -1,3 +1,25 @@
+New in 2011.07
++ fractional powers of negative numbers now result in Complex numbers
++ obtain spectests from a specific branch of the `roast' repo
++ fix bug that prevented build on systems with little RAM
+
+New in 2011.06
++ added take-rw built-in
++ numerous build system improvements
++ assignment now evaluates arguments right-to-left
+
+New in 2011.05 release
++ added a call counter for builtins in Perl 6-level subroutines
++ gcd (greatest common divisor) and lcm (largest common multiple) operators
++ build system improvements
++ added --ignore-parrot-rev option to Configure.pl
++ Configure.pl now creates "config.status" file
++ fixed relational operators when used with NaN
++ implemented Int.base
++ speedup smart-matching against numbers and Str.comb with default arguments
++ added RAKUDO_SUBLOG environment var for tracking subroutine calls
++ overall performance speedups
+
 New in 2011.04 release
 + implemented Str.indent
 + A new, much simpler API and implemention of IO::Socket::INET