class library: allow NamedControl.new to return non-arrayed Lag
plugins: EnvGen - remove duplicated code

Signed-off-by: Tim Blechmann <tim@klingt.org>
plugins: EnvGen - unify envgen perform implemementation
Env: provide new step2 shape, which steps to a value at the end of a shape

the semantics of Env.xyc for \step is very awkward when using, because \step directly
jumps to the end value of a segment. this means that Env.xzc([[0, 0, \step], [1, 1, \step]])
will have the value 1 between time 0 and 1.
using \step2 instead of \step, the value between 0 and 1 will be 0, and it will jump to 1
at time 1

Signed-off-by: Tim Blechmann <tim@klingt.org>
Env: rename step2 to hold

'hold' shares the analogy of sample&hold and is therefore more expressive
than step2

Signed-off-by: Tim Blechmann <tim@klingt.org>
EnvGen: fix .kr method

Signed-off-by: Tim Blechmann <tim@klingt.org>
sclang/identDict_put: test if object is mutable before changing

this fixes #1007
converted to JITGui, works with Qt, quicker filter response.
more tweaks to History, gui and help files;  NdefGui
fix filepath typo in os x readme file
help: SequenceableCollection: obtain and instill examples
Merge pull request #1015 from seansay/fix-typo

fix filepath typo in os x readme file
Merge pull request #1012 from mortuosplango/identdict-freeze-fix

sclang/identDictput: test if object is mutable before changing
Merge pull request #975 from timblechmann/topic/env_step2

plugins: EnvGen: refactor and simplify ugen implementation and add a \hold shape.
help: add loop node example to EnvGen
Classlib: NumChannels: Round up the clump size for fractional division
Merge pull request #974 from totalgee/master

class library: remove unnecessary conversion of lag argument to array (fixing issue 973)
class library: signal blend returns a signal. Fixes issue #1004
class library: add a more informative error message to scope

When the computer sleeps, the shm interface may get lost. Then the server, if not internal, can't scope. Instead it tries to use the internal stethoscope, which now throws a more informative error.
Note: the GUI redirects in this case are extremely intransparent and should be refactored.
class library: change from spaces to tabs in QT related files

Instead of spaces, tabs are standard in the sc class libraray. This change avoids unintended mixing of conventions.