couple of doc fixes
reorg toplevel doc
Fix doc typo: langauge -> language
Merge pull request #511 from lucaswerkmeister/patch-1

Fix doc typo: langauge -> language
Fix spelling mistakes

Found with

    find -name '*.ceylon' -exec grep '^\(    \)*\( \|"\)[^ ]' {} + > tmp

to find text that's most likely documentation (starts with 4n + 1
spaces), and then

    hunspell tmp

to spellcheck the text. (Most of the unknown words were still not actual
typos (references to classes and functions), but this is still better
than just spellchecking the entire code, where there would be even more
such false positives.)
Merge pull request #512 from lucaswerkmeister/master

Fix spelling mistakes
metamodel #506: fix Container type parameter of all operations of ClassOrInterface
Test for #506: fix Container type parameter of all operations of ClassOrInterface
Test for #309 which were fixed by #506
FreePackage: fix for #469: Errors logged about FreePackage.filteredMembers
Test for #477 which already was fixed
improve docs
Updated reference to `Logger`now that it has been moved to common
Now using `LoaderJULLogger` from the compiler project instead of the old `JULLogger` from the CMR
Module/package descriptors got renamed for ceylon/ceylon-compiler#1723
doc refreshes
Fix Sequence.Reverse.rest

For the corner case size==1, Sequence.Reverse.rest would return the
sequence itself instead of the empty sequential.

(Introduced in bfde4b5, where a completely wrong implementation was
replaced by the almost correct one.)
Add test for Sequence.Reverse.rest corner case bug

(The bug was fixed in 28a1141.)
Merge pull request #514 from lucaswerkmeister/fixSequenceReversedRest

Fix Sequence.Reverse.rest
remove native impl of Tuple.reversed