remove .gitignore files and symbolic links/aliases (#3421)

* remove symbollic links in the src directory as they are no longer
  working with the out-of-source build
* remove .gitignore in the documentation (is build in build folder not
  needed)
* remove CMake folders as they are also no longer present in the source
  directory

Closes #3420.

.gitignore

@@ -4,11 +4,8 @@ commit.h
 .*.swp
 Session.vim
 package-config/osx/binary/task
-/build*/
+/*build*/
-install_manifest.txt
-_CPack_Packages
 patches
-*.exe
 tutorials
 .prove
 /target/

doc/man/.gitignore

@@ -1,4 +0,0 @@
-task-color.5
-task-sync.5
-task.1
-taskrc.5

src/.gitignore

@@ -1,6 +1 @@
-*.o
-Makefile.in
-debug
-calc
-lex
 liblibshared.a

src/cal

@@ -1 +0,0 @@
-task

src/calendar

@@ -1 +0,0 @@
-task

src/tw

@@ -1 +0,0 @@
-task