Documentation update

Rework for Doxygen >1.8. Moved large parts of the documentation to a
simplified format, making use of Markdown enhancements and fixing bad
long options.

doc_src/umask.txt

@@ -1,25 +1,27 @@
 \section umask umask - set or get the file creation mode mask
 
 \subsection umask-synopsis Synopsis
-<code>umask [OPTIONS] [MASK]</code>
+\fish{syn}
+umask [OPTIONS] [MASK]
+\endfish
 
 \subsection umask-description Description
 
-\c umask displays and manipulates the "umask", or file creation mode mask,
+`umask` displays and manipulates the "umask", or file creation mode mask,
 which is used to restrict the default access to files.
 
 The umask may be expressed either as an octal number, which represents
 the rights that will be removed by default, or symbolically, which represents
 the only rights that will be granted by default.
 
-Access rights are explained in the manual page for the \c chmod(1) program.
+Access rights are explained in the manual page for the `chmod`(1) program.
 
 With no parameters, the current file creation mode mask is printed as
 an octal number.
 
-- <code>-h</code> or <code>--help</code> prints this message.
-- <code>-S</code> or <code>--symbolic</code> prints the umask in symbolic form instead of octal form.
-- <code>-p</code> or <code>--as-command</code> outputs the umask in a form that may be reused as input
+- `-h` or `--help` prints this message.
+- `-S` or `--symbolic` prints the umask in symbolic form instead of octal form.
+- `-p` or `--as-command` outputs the umask in a form that may be reused as input
 
 If a numeric mask is specified as a parameter, the current shell's umask
 will be set to that value, and the rights specified by that mask will be
@@ -30,21 +32,21 @@ not the inverse, should be specified. A symbolic mask is a comma
 separated list of rights. Each right consists of three parts:
 
 - The first part specifies to whom this set of right applies, and can
-be one of \c u, \c g, \c o or \c a, where \c u specifies the user who
-owns the file, \c g specifies the group owner of the file, \c o
-specific other users rights and \c a specifies all three should be
+be one of `u`, `g`, `o` or `a`, where `u` specifies the user who
+owns the file, `g` specifies the group owner of the file, `o`
+specific other users rights and `a` specifies all three should be
 changed.
 - The second part of a right specifies the mode, and can be one of \c
-=, \c + or \c -, where \c = specifies that the rights should be set to
-the new value, \c + specifies that the specified right should be added
-to those previously specified and \c - specifies that the specified
+=, `+` or `-`, where `=` specifies that the rights should be set to
+the new value, `+` specifies that the specified right should be added
+to those previously specified and `-` specifies that the specified
 rights should be removed from those previously specified.
 - The third part of a right specifies what rights should be changed
-and can be any combination of \c r, \c w and \c x, representing
+and can be any combination of `r`, `w` and `x`, representing
 read, write and execute rights.
 
-If the first and second parts are skipped, they are assumed to be \c a
-and \c =, respectively. As an example, <code>r,u+w</code> means all
+If the first and second parts are skipped, they are assumed to be `a`
+and `=`, respectively. As an example, `r,u+w` means all
 users should have read access and the file owner should also have
 write access.
 
@@ -52,7 +54,7 @@ Note that symbolic masks currently do not work as intended.
 
 \subsection umask-example Example
 
-<code>umask 177</code> or <code>umask u=rw</code> sets the file
+`umask 177` or `umask u=rw` sets the file
 creation mask to read and write for the owner and no permissions at
 all for any other users.